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#51 |
Registered User
Join Date: Mar 2008
Location: ky
Posts: 6
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Re: 350 or 400?
go with the 400 but put a 350 crank in it 5'7 rods 400 pistons and then you will have a power house
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#52 |
Registered User
Join Date: Dec 2006
Location: medford oregon
Posts: 152
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Re: 350 or 400?
i like the 350's myself but then again im still young and have never felt the power of a 400
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Dustin if its not broke dont fix it ![]() |
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#53 | |
I have a radical idea!
Join Date: Jan 2005
Location: Sweet Home Alabama!
Posts: 6,513
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Re: 350 or 400?
Quote:
Another thing that surprisingly hasn't been mentioned is keeping a 400 SBC cool. We have established that some are prone to cracking, but alot of that is due to fact that most of the time they are harder to keep cool that the other small blocks. I couldn't tell you how many 70's van I've seen that either had 400's that were replaced or had a cracked 400 in them. I've also seen 400's that didn't run any warmer than the 350 or 305 they replaced. Like the cracking issues, it boils down to having a good block.
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'67 C-30 Dually Pickup 6.2 Turbo Diesel, NP435 ‘72 C-10 SWB , 350 4bbl, TH350 '69 C-10 SWB , 250 L6, 3 OTT '69 GMC C3500, dump truck, 351 V6, NP435 '84 M1009 CUCV Military Blazer 67 C-30 Turbodiesel build thread http://67-72chevytrucks.com/vboard/s...d.php?t=254096 My trucks http://s226.photobucket.com/albums/d...ediafilter=all Member of the 1-Ton Club! |
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#54 |
1972 Chevrolet SWB
Join Date: Jan 2008
Location: FT Smith AR
Posts: 512
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Re: 350 or 400?
No problems here with cooling with a 2 core radiator in my 67 Impala with solid 4 blade fan and shroud,nor my 72 Chevy it was in for a while with 4 core rad,shroud and same solid 4 blade fan. Yes they are known to heat problems but that is mainly because they are not being cooled properly.mine had double humps with 67 cc and I drilled the steam holes myself.
Again I neither prefer a 350 or 400 when they are brought in frt of me because I have built and ran them both,now choosing between 283 307 305 vs the 350 400......no brainer.
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My New thread with pics (not my build thread yet.) ![]() http://67-72chevytrucks.com/vboard/s...46#post2573646 1972 Chevrolet 1/2 ton short wide bed,68 frt clip Project. 1980 Camaro Inherited when father passed,68K Miles 2003 Ford Mach1 FUN as Hell!! 2002 Dodge Ram 5-8 slam Rolling BillBoard (Gone not forgot) 2004 Dodge Ram HEMI 10" lifted on 37's and 2wd. |
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#55 | |
Registered User
Join Date: Jun 2007
Location: oregon
Posts: 1,069
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Re: 350 or 400?
Quote:
exactly my point! ![]()
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69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears: ![]() |
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#56 |
Registered User
Join Date: Mar 2004
Location: CA
Posts: 2,057
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Re: 350 or 400?
just another opinion, and you know everyone has an opinion
mine is to keep an open mind, not to close the door on somthing just becasue of stories, and b.s. bench racing people do. ive seen plenty of good running engines people talk trash about for one reason or another. so all in all, yes i'll agree the 400 has been known to have its flaws, but does that make ALL 400's scrap? hell no ![]() |
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#57 |
Registered User
Join Date: Jun 2007
Location: oregon
Posts: 1,069
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Re: 350 or 400?
Isn't it something that the simple fact that the title here is entitled "350 or 400 ?" and now there are almost 5 dozen posts!
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69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears: ![]() |
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#58 |
1967newheartbeat
Join Date: Mar 2008
Location: rentz , georgia
Posts: 96
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Re: 350 or 400?
350 or 400 ? It' really simple, do what you feel comfortable with because hey it's your money , your truck , and your time . So no matter what any of us say the last opinion that ultimately matters is yours.
I' m a Chevy man and as long as it's Chevy you can't go wrong as far as I'm concerned. ![]() |
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#59 |
Registered User
Join Date: Jun 2007
Location: oregon
Posts: 1,069
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Re: 350 or 400?
If you have a 350 now and it works.................why go to the 400 with no flywheel....................and the unknown potential trouble.
This is a no brainer to me!
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69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears: ![]() |
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#60 |
Senior Member
Join Date: Sep 2004
Location: Terrell, TX
Posts: 1,967
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Re: 350 or 400?
While the 400's had trouble cooling there are solutions. I foggily remember certain heads/blocks that were drilled differently to help with cooling and those eliminated the problems.
All that said, if you want more reliability, stick with the 350 and toss in a cam kit for more HP.
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Kelly '05 GMC Sierra SLE Z71 Bone stock except for new bed rail caps. |
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#61 |
Registered User
Join Date: Jun 2007
Location: Smyrna, GA
Posts: 709
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Re: 350 or 400?
Number's matching are hard to find these days. That gets my vote. Especially since that 350 hasnt been bored out, etc... you still have to oportunity to do so down the road and build it the way you want. Stick with the 350 unless you just want more torque.
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Rottenwood Garage 1970...71...72 C1500 aka Orange aka Sideshow Bob 540 BB Straub Roller Cam, AFR Magnums, XP 950, TKO 600 2 Tons of Fun |
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#62 | |
Registered User
Join Date: Mar 2007
Location: Phoenix, Arizona
Posts: 175
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Re: 350 or 400?
Quote:
If that thing is burning a quart every 1k, that is excessive, it's got more history than 60 or 70 unless he beat it to death, plus matching numbers on the 350 is work more than $250 if you every plan on selling. If you have to have the 400, pull and store to 350 until the 400 blows, which with the oil it's burning, it should take long. ![]()
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1972 c-20, 350/350, dana 60 w/456 gears(no Posi) |
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#63 | |
Registered User
Join Date: Jun 2007
Location: oregon
Posts: 1,069
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Re: 350 or 400?
Quote:
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69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears: ![]() |
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#64 | |
Registered User
![]() Join Date: Jan 2007
Location: Virginia
Posts: 411
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Re: 350 or 400?
Quote:
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#65 | |
I have a radical idea!
Join Date: Jan 2005
Location: Sweet Home Alabama!
Posts: 6,513
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Re: 350 or 400?
Quote:
The 400 SBC while loved by racers and hot rodders, was a nightmare for GM in fleet vehicles and commercial trucks. You are understating the differences though. Those seemingly minor modifications make all the difference in the world. There is really no comparison between them. Yes, they are both siamesed cylinder SBC's, but the race blocks are FAR superior. In addition to those improvements, the race blocks have thicker decks, beefier main webbing and beefier casting around the lifter bores.
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'67 C-30 Dually Pickup 6.2 Turbo Diesel, NP435 ‘72 C-10 SWB , 350 4bbl, TH350 '69 C-10 SWB , 250 L6, 3 OTT '69 GMC C3500, dump truck, 351 V6, NP435 '84 M1009 CUCV Military Blazer 67 C-30 Turbodiesel build thread http://67-72chevytrucks.com/vboard/s...d.php?t=254096 My trucks http://s226.photobucket.com/albums/d...ediafilter=all Member of the 1-Ton Club! Last edited by 67_C-30; 03-22-2008 at 12:15 PM. |
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#66 | |
Registered User
Join Date: Jun 2007
Location: oregon
Posts: 1,069
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Re: 350 or 400?
Quote:
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69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears: ![]() |
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#67 |
Registered User
Join Date: Apr 2004
Location: N.E. MO
Posts: 1,749
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Re: 350 or 400?
I'm votin for the 400.
Why, because the term "numbers matching" makes me ill. There's not a vehicle on the planet that is made better by what numbers are stamped on it. And that, my friends, is the fact and only fact.
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72 C20 4X4 454 4 speed 89 Trans Am (was) 305 TPI 700r4 93 C1500 2wd Extended cab 350 700r4 98 Sonoma (TPI outa the Trans Am) 03 Yamaha 660 Raptor 03/04 660 Raptor 07 700 Raptor 85 Honda Odyssey |
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#68 |
Registered User
![]() Join Date: Jan 2007
Location: Virginia
Posts: 411
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Re: 350 or 400?
[QUOTE=67_C-30;2638568]Every engine you list was superceded by a bigger engine except the 302. The 350 replaced the 327 and and the 454 replaced the 396/402/427. The 302 wasn't really replaced by anything because it was of creature of comformity. SCCA rules mandated a 305 cu in rule limit at that time, and the 302 was only built to fall within those guidelines. That is the only reason it ever existed. The 305 cu in limit was raised after the 1969 season making the 302 obsolete.
The 400 SBC while loved by racers and hot rodders, was a nightmare for GM in fleet vehicles and commercial trucks. Yes they were all replaced by larger motor but, thats not what i'm getting at here. What i'm saying is that people shouldn't put down a 400 just because they are far less common than a 350, 400 were the biggest of the small blocks so they wouldn't have been replaced during the bad smog years by anything bigger, this the time the 305s came out. With some people talking smack about the 400 it leads me to think that 1 they have never had one or 2 they were one the ones who destroyed one due to overheating, and yes the race blocks are alot better, but i've seen plenty of 550 to 625hp 400s with stock blocks and plenty of these lasted 5+ year in full race apps. so for some to say that a 400 is a gm failure i think they need to read a more into it. But, then the less people who like um the more i can collect! ![]()
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#69 | |
Registered User
Join Date: Mar 2004
Location: CA
Posts: 2,057
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Re: 350 or 400?
Quote:
and to say words of wisdom outnumber us IS a dis, i feel that i have much more experiance than most when it comes to doing machine work and biulding engines, as i said ive worked off and on in an automotive machine shop for years. and built HUNDREDS of engines of all sizes, from 265's to 434 small blocks. the fact is, the 400 is a fine engine. ther have been some probleoms but several were self inflicted becasue of misuse of heads without steemholes and overheating. and the oil burning has been discussed and the real probleoms are evident: the rod length. |
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#70 |
I have a radical idea!
Join Date: Jan 2005
Location: Sweet Home Alabama!
Posts: 6,513
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Re: 350 or 400?
This thread had skewed WAY off topic. This has turned into a general 350 vs 400 debate, but the original poster simply wanted an opinion on whether he should sell his original 59K mile 350 to get a 400 that is burning a of quart every 1000 miles. He said with his financial situation that he could not have both, so he had to make a decision between the two. I recommended (and still do) to keep his perfect running, low mileage, original 350. I see no reason to take a chance on the 400 he really knows little about except its burning oil, because it sounds like in his financial situation that if the lunches the 400, he couldn't easily replace it.
Now, we can go back and forth for all day on the 400's, but the fact is that many have cracked, and the main reason is CORE SHIFT. Core shift is variation from specified dimensions of the block due to a change in position of the core or misalignment of cores in the casting process. All production engines have a degree of core shift, but the 400 is more prone to failure because of the already thin water jackets. This was the main design flaw. As I said before though, when you get a 400 with very little core shift, it is a great engine. There are tons of them out there that have little core shift, and are great platforms for HP engines. However, there are lot of them with significant shift. These are the ones that crack easily. Some don't even have to overheat. There were low mileage engines when almost new with a lot of core shift that cracked for no apparent other than the cylinder wall was less that .100" and just couldn't handle the stress of pulling, high RPM etc. If you know what you are looking for, you can even tell to some degree if the block has a lot of shift. You can pull the timing cover off and look at the machined area around the camshaft. If one side is or the other is significantly wider than the other, this is an indication of core shift. This of course is not an exact science, but I promise you if you have block that is .100 wider on one side of the parting line, it will sonic check very thin. I have also built engines for drag cars, street/strip cars, circle track, light truck diesels and even some speed boat engines along with I couldn't tell you how many mild or stock engines. Building engines paid my way through college and has supplemented my income as long as I have been working. I have been a machinist for 12 years and currently program/operate a Mori Seiki SL-35 and SL-25 CNC lathe as well as a MH-40 horizontal mill along with experience of the manual mills, lathes, boring machines, surface grinders, and a Hitatchi wire EDM machine. I have seen and built good 400's and I've had to chuck several boat anchor 400's. A good thick 400 is a great engine, but you have to be careful when buying them, especially if you can't hear them run or be able to check the oil for water. Swap meet 400's have broken a lot of hearts!
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'67 C-30 Dually Pickup 6.2 Turbo Diesel, NP435 ‘72 C-10 SWB , 350 4bbl, TH350 '69 C-10 SWB , 250 L6, 3 OTT '69 GMC C3500, dump truck, 351 V6, NP435 '84 M1009 CUCV Military Blazer 67 C-30 Turbodiesel build thread http://67-72chevytrucks.com/vboard/s...d.php?t=254096 My trucks http://s226.photobucket.com/albums/d...ediafilter=all Member of the 1-Ton Club! |
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#71 | |
Registered User
Join Date: Mar 2004
Location: CA
Posts: 2,057
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Re: 350 or 400?
Quote:
my father has been a machinist for 30 years started on maunual bridgeport milling machines and old school leblonde lathes, and runs similar CNC machines daily and has no experiance doing atomotive machinig, and if asked to run the CK-10 that i run almost every weekend, he would have trouble. but yes, this has strayed a LONG ways from the original topic, and should be put to rest. |
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#72 |
Saving 1 truck at a time!
Join Date: Aug 2001
Location: Kent, WA
Posts: 6,465
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Re: 350 or 400?
Geez...at that price buy the 400 and keep your 350. Always have a spare for these old trucks...it is easy to swap them out.
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'68 C20 Longhorn 50th Anniversary 400/TH400 '68 C20 Longhorn 50th Anniversary 468/TH400w/buckets '72 C20 Halfhorn (Longhorn w/o cab and front clip) '69 Flxible Cruiser (look up ugly in the dictionary) |
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#73 | |
I have a radical idea!
Join Date: Jan 2005
Location: Sweet Home Alabama!
Posts: 6,513
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Re: 350 or 400?
Quote:
You're right that it is much different that automotive machining, but I have experience in both. The bulk of my automotive has come doing work on the boss' Super Late Model dirt engines. I have done boring/honing, align boring, decking, angle milling heads and intakes. fly cutting valve reliefs, you name it. A few weeks back I even put a fuel pump push rod hole in newer engine block for one of his buddies so he could run a mechanical fuel pump on a hobby stock car. He has the equipment I listed above just for his toys! ![]()
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'67 C-30 Dually Pickup 6.2 Turbo Diesel, NP435 ‘72 C-10 SWB , 350 4bbl, TH350 '69 C-10 SWB , 250 L6, 3 OTT '69 GMC C3500, dump truck, 351 V6, NP435 '84 M1009 CUCV Military Blazer 67 C-30 Turbodiesel build thread http://67-72chevytrucks.com/vboard/s...d.php?t=254096 My trucks http://s226.photobucket.com/albums/d...ediafilter=all Member of the 1-Ton Club! Last edited by 67_C-30; 03-27-2008 at 07:20 PM. |
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#74 |
Will it run today?
Join Date: Feb 2007
Location: DFW, Texas
Posts: 272
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Re: 350 or 400?
I have to vote 350. If money is that tight, why take the chance. The Chevy small block 350 is the most successful racing engine in history for a reason. It is durable and reliable, the two hallmarks of cost effective driving. It will be better on gas mileage, cheaper to rebuild, easier to find parts, so on, and so forth.
I look at like this. The 350 is a good, loyal, attractive wife. The 400 is the siren next door trying to get your attention. The 400 would really make you go, but for how long, and at what expense. Stick with the good woman by your side and enjoy a long happy life together. Best of luck to you! David
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Jaws, the 1971 Chevy Cheyenne Longbed. She's big, grey, and has an insatiable appetite! |
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#75 |
Registered User
Join Date: Jun 2007
Location: oregon
Posts: 1,069
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Re: 350 or 400?
I have been a machinist since 1970............that's 38 years my friends! What I have realy enjoyed watching through the years is when "Captain Engine Lathe" jumps up and turns the conversation into "machinistvsmachinist".................
so now we are doing that and yes we missed the point didn't we of this whole topic... ![]() kinda like the weekend BBQ and someone can't get the BBQ to light up- ...............................someone jumps up "I'm a machinist!!!!!!!!!!!!" and off we go!!!!!!!!!!!!! ![]()
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69 K-20 cloned to a 67 with front clip and some other stuff. 383 .040 over Crane roller cam lifters and rockers ,1.6 intake ratio, Open chamber heads, 9.5-1 compression ratio, 2.02 intake valves , Edelbrock performer Air Gap manifold Carter AFB performer 750cfm, MSD ignition, SM465 NP205 4.10 gears: ![]() |
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