|
05-09-2017, 04:32 PM | #1 |
Registered User
Join Date: Apr 2017
Location: Sacramento, CA
Posts: 53
|
Rebuild advice
So, I want to rebuild the 400 big block or at least I think I do and the TH400 transmission. Nothing insane but maybe 450 HP or so. The other option would be to throw another tranny and engine from something newer but I kind of want to keep #'s together.
I was thinking EFI but I don't know where to start. I assume a top end kit and some pistons, get the block to a machine shop to be checked out and cleaned up. Any suggestions on heads/top end kit, EFI and what to do to the transmission and perhaps the rear end? I should add on a budget and I'd like to drive it often and last a long while Last edited by Haru; 05-09-2017 at 04:40 PM. |
05-09-2017, 04:59 PM | #2 |
Registered User
Join Date: Jun 2015
Location: Denver, co
Posts: 66
|
Re: Rebuild advice
whats your budget?
|
05-09-2017, 05:22 PM | #3 |
Registered User
Join Date: Apr 2017
Location: Sacramento, CA
Posts: 53
|
Re: Rebuild advice
|
05-09-2017, 05:25 PM | #4 |
Senior Member
Join Date: Jan 2001
Location: Orem, Utah
Posts: 7,933
|
Re: Rebuild advice
I wouldn't do all that work on the top end without making sure the bottom end is solid first.
|
05-09-2017, 05:08 PM | #5 |
Registered User
Join Date: Oct 2011
Location: jackson michigan
Posts: 755
|
Re: Rebuild advice
I don't think our trucks have matching numbers per say.
|
05-09-2017, 05:28 PM | #6 |
Registered User
Join Date: Apr 2015
Location: East Tn (In the heart of the Smoky Mtns)
Posts: 1,875
|
Re: Rebuild advice
Advice 101:
Don't go crazy on the cam, though it sounds cool, big cams will cause headaches If this is the first rebuild, go with the least amount of bore needed to get rid of the lip. Talk to the machinist, and tell him how you plan to use the truck. Take the heads to the same guy to be surfaced. At least have your rocker studs pinned, on a mild rebuild, screw ins are not absolutely needed. Do you plan to assemble it yourself? If so I have some other things I've learned from experience. |
05-09-2017, 05:32 PM | #7 |
Registered User
Join Date: Jun 2015
Location: Denver, co
Posts: 66
|
Re: Rebuild advice
5k would work for a stock rebuild (depending on machining prices in your area). double that for any kind of performance build I would say. I would go with a complete package from edelbrock if I were you. They have a lot of engineering behind them and they work. use quality pistons and stock bottom end to save some $$. If it were my truck, I wouldn't bother with the original engine (these trucks will never be true "collectors items" and the original engine doesn't really help with the value) I would go with a modern engine and either a factory fuel injection, or one from megasquirt. Here at my local pull your own parts, I can get a complete engine for 500 bucks, wiring harness is like 20 i think, and a computer is 20. transmission is 250 so for under 1g I can have 2/3 of my drivetrain done. that leaves quite bit of room for performance upgrades.
|
05-09-2017, 06:37 PM | #8 |
Registered User
Join Date: Aug 2016
Location: Lake Forest, CA
Posts: 2,177
|
Re: Rebuild advice
Built top end will get you power.
Built bottom end will get you piece of mind.
__________________
"Work hard, use your vacation days." 1970 C15 GMC Long Bed 1986 C20 Scottsdale 1983 K2500 Sierra Classic Suburban 6.2 Instagram: C10sofOC |
05-09-2017, 06:50 PM | #9 |
Registered User
Join Date: May 2016
Location: Henderson NC
Posts: 975
|
Re: Rebuild advice
Are you dead set on it being a big block? Small blocks and parts are cheaper.
|
05-09-2017, 08:14 PM | #10 |
Registered User
Join Date: Apr 2017
Location: Sacramento, CA
Posts: 53
|
Re: Rebuild advice
I was..until reading these comments. I felt like I should keep the engine/transmission but sounds like it really doesn't matter. Maybe I need to find a low mileage wrecked ZL1 Camaro for cheap lol
|
05-09-2017, 09:48 PM | #11 |
Registered User
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
|
Re: Rebuild advice
I'd throw a larger block at it - 454 or 502 or 540. Displacement is easy torque/power, but getting an honest 450 out of a 396 is going to be tough and make for one skittish engine that sucks to drive on the street. It's -possible- with a roller cam and good heads, but not easy. 375 is pretty typical. 400 is harder. 450 is a reach.
It's much easier with more cubes, and that way you can save your original block too. They're not serialized but they are coded to your application (1970 402 Automatic, for example).
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible |
05-09-2017, 10:15 PM | #12 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,722
|
Re: Rebuild advice
Big blocks not so popular right now and can be picked up relatively inexpensively. What's wrong with the motor now? If the bore isn't barreled or tapered, you might be able to hone and put rings in it. Polish the crank and have the heads rebuilt you'd be in it for less than $2k.
BUT, 450 hp talk changes that conversation dramatically. I just put a 427 together for my '69. I rebuilt the stock heads with new valves, ponied up for a Comp Hydraulic roller, used Scat rods instead of rebuilding the stockers and a rebuild kit from Summit that had the L2300F forged pistons. $2500 in cam and heads. $1000 in rods on the pistons, vat, bore, etc. $1000 for the rebuild kit and the rods. Call it $4500 in the long block. $300 for an intake, $600 for a carb, $200 for an oil pan, $150 for a distributor with melonized gear. $200 for SFI balance, $50 SFI flywheel.Call it $5900 + incidentals. My "budget" was $4500 and I got it done for $6k-ish. Which is only off about 30% which I consider better than average miss! You might find a deal with a used motor. I bought another 427 almost identical to the one I build on Craigslist with a Marine hydraulic roller instead of the Nitrous hydraulic roller. It has damaged bearings but don't look spun. I gave $900 for it without distributor or carb. And it will need an oil pan because the marine one won't work in a truck AND it's tweaked. If it all checks out (and like a collision there is always hidden damage) I'll have it going for $2k or a bargain compared to the first one. Or it will have to come completely apart and I know what that costs... Better yet, find a running/driving Suburban with TH400 and 454 that you know is in good conditions and swap into your truck. That will be way cheaper in the long run. Subs aren't usually driven as hard as trucks, especially duallys where the 454 is most common. This is where LS swap talks comes in, because you can buy a complete running truck for $4k and get OD and FI.
__________________
44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax |
05-09-2017, 11:55 PM | #13 |
Registered User
Join Date: Jun 2013
Location: Somewhere
Posts: 3,084
|
Re: Rebuild advice
EFI on a budget. Won't happen.
A factory big block in one of these trucks is to be treasured, if not valued. Maybe you should clean it up or let it go to someone who'll treasure it. Snag an SBC truck, drop an LS (not as easy as they say) in and rock. Or, clean up the old beast, fix the brakes, steering, suspension, change all (more than you think) fluids, and do some cosmetics to the interior. That alone is what $1500-2k? Try fixing it a bit at a time while driving it and enjoying the fixes. |
05-10-2017, 01:35 AM | #14 | |
Registered User
Join Date: Jun 2015
Location: Denver, co
Posts: 66
|
Re: Rebuild advice
Quote:
|
|
05-10-2017, 04:39 AM | #15 |
Registered User
Join Date: Mar 2006
Location: Latrobe, Pa. 15650
Posts: 344
|
Re: Rebuild advice
I took my 396 to the machine shop and told him to rebuild it. I bought a set of .60 over Wiseco pistons off the internet a guy had custom made for his 396. The shop cut the crank .10 .10 and polished and balanced it. Resized the rods and installed the pistons. The block was completely gone over. Heads were enlarged with the bigger stainless steel valves. He started putting the engine together and there was a problem. At tdc, the pistons were .250 below the deck. Now what. We never thought of where the pin was located on the pistons. The machinist said about using 454 parts. He had an Eagle crank and rods laying around someone didn't want. With a .60 bore and 454 stroke, the cubes came out to be 440. If I didn't have to pay for the second balancing, The total came to $3,300. Airgap intake, Quikfuel carb, MSD, Lunati Bracket Master cam kit, and of course Hooker headers, and a few odds and ends. I had $5,500 in this motor. I had it dyno and it made 522 hp and 541 pounds of torqe. This 3,900 pound long bed C10 ran low 12,s all day. The machine shop told me to put better heads on it and really have some fun. The big block is a lot of fun. We show this truck also. Street and strip is the ticket.
|
05-10-2017, 12:22 AM | #16 |
Registered User
Join Date: Nov 2006
Location: KINGSPORT,TN.
Posts: 3,035
|
Re: Rebuild advice
its a 402, keep it stock
__________________
I BELIEVE IN JOHN 3:16 |
05-10-2017, 03:11 PM | #17 | ||
"I ain't nobody, dork."
Join Date: Sep 2007
Location: Whidbey Island, Washington
Posts: 8,946
|
Re: Rebuild advice
Yup.
I was wondering what a 400 Big Block was... Gary
__________________
'cuz chicks dig scars... My 1972 GMC 1500 Super Custom (Creeping Death) "long term" build thread. The Rebuild of Creeping Death after the wreck Quote:
Quote:
|
||
05-10-2017, 01:24 PM | #18 |
Registered User
Join Date: Apr 2017
Location: Sacramento, CA
Posts: 53
|
Re: Rebuild advice
Engine runs, or so I was told and rebuilt at some point. I'l need to get the oil pan on it and see..Maybe this weekend. Thanks all for the input, I'll most likely keep whats in it and go from there. Now I need to find a local transmission shop. Well, if it is indeed dead as the previous owner stated.
|
05-10-2017, 03:03 PM | #19 |
Registered User
Join Date: May 2017
Location: rye nh
Posts: 8
|
Re: Rebuild advice
looking for a transfer case for 1962 1/2 ton 4x4
|
05-10-2017, 05:09 PM | #20 |
Registered User
Join Date: Aug 2016
Location: Lake Forest, CA
Posts: 2,177
|
Re: Rebuild advice
Start your own thread
__________________
"Work hard, use your vacation days." 1970 C15 GMC Long Bed 1986 C20 Scottsdale 1983 K2500 Sierra Classic Suburban 6.2 Instagram: C10sofOC |
Bookmarks |
|
|