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12-07-2012, 08:27 PM | #1 |
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Which engine to get?
Hey guys,
It's been awhile since I have been on here, you know, life took over. So here is my question: I've got a 72 3/4 ton suburban with the big block. Runs great, but gas mileage sucks (6-9 mpg). Soon going to be my daily driver. So I'm looking into an Lsx swap. I've been trying to read as much as I can, but it's to a point now where there is so much info, I can't figure out what's what anymore. Here are my options: 2011 5.3 with 500 miles, already has stand alone harness and PCM with mag and pedal. Mated to a built th350. Price: 2500.00 2006 6.0 with 70k miles with harness and tranny and PCM and pedal for 2500.00 Which would you get if you had the choice? Should I get the overdrive tranny? Will the 3 speed really hurt mpg that much? Will the th350 hold up to the weight of the suburban? Also, let me see of I understand everything else I need for the swap: Fuel pump (walbro) Fuel regulator (99+ c5 vette) Motor stands ( which ones are the best, and will work with my 3/4 ton frame?$ Exhaust work Which exhaust manifolds did we decide work? Sanden AC compressor brackets (already have vintage air front and rear) Power steering hose adapters (where to buy from) Electric fans (I thought there were some that mounted to the stock '72 4 core radiator?) Tranny mount ( buy new or adapt my th400 crossmember?) Driveshaft modified Anything else I'm missing? Thanks for the help guys!! Posted via Mobile Device
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1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE |
12-07-2012, 09:37 PM | #2 | |
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Re: Which engine to get?
Quote:
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Mike 2001 Dakota R/T - Silver CC - 1 of 1671 •360 w/46RE •392 limited slip 1972 Chevy Suburban - Turquoise/Black 1969 Chevy C/10 - Blue LWB •350 w/ 700R4 •3.73 posi •PS PB A/C - SOLD Using your turn signal is not "giving information to the enemy" 67-72 FAQ |
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12-08-2012, 12:52 AM | #3 |
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Re: Which engine to get?
What rear end and gears do you have? With the right gears and tune you should be able to get 12-14 mpg out of that big block.
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68' C20. 283CI w/55CC 305HO heads, NP435 Close Ratio, Corp. 14 bolt FF 3.21, 75' front end swap (everything but the X-member). |
12-08-2012, 01:30 AM | #4 |
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Re: Which engine to get?
If I recall correctly it is a Dana 60 with 3.54 ratio. It also has an edelbrock 750 which I know is running a little rich. Everything else is stock except for distributor. I think part of the problem is where I live is near the base of the mountains. Everywhere I drive has a slow steady grade up wards. I'm always driving up hills it seems. The suburban is also pretty heavy. I haven't heard of anyone getting 12-14 with one of these big blocks, but I haven't seen everything either.
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1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE |
12-08-2012, 02:25 PM | #5 | |
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Re: Which engine to get?
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Good luck, & keep us informed which way you decide. sam |
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12-08-2012, 02:55 PM | #6 | |
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Re: Which engine to get?
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NAME: TRAVIS TRUCK: BRUISER 71 C/10 SWB 3.5/5" drop 4.11 GEARS. F.A.S.T. BBC 408 496hp/479ft/lb JAKES 4L80E TCI TCU PTC 10.5" 2800 STALL My build thread: http://67-72chevytrucks.com/vboard/s...30#post5779530 |
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12-08-2012, 07:10 PM | #7 |
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Re: Which engine to get?
The 5.3 would be my choice.
All the 6.0's that I have had get horrible fuel mileage and rattle like a diesel. I'm sure this will miff off the 6.0 fans on here, and I'm sure there is some 6.0 guru out there who gets 50 mpg. Out of a 500 h.p. 6.0 As the owner of an auto salvage for 23 years, I have sold lots of 5.3 and 6.0 engines. I am a huge fan of the 5.3 and not so much the 6.0 Posted via Mobile Device
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MY BUILD THREAD http://67-72chevytrucks.com/vboard/s...d.php?t=423629 1969 custom/10 swb--SOLD 1968 swb 50th anniv.--SOLD 1967 camaro ss/rs..LS-6-speed, 16-year long project 1956 chevy nomad 1955 chevy 210 2-dr sedan 1978 el-camino ss 1-owner |
12-08-2012, 09:02 PM | #8 | |
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Re: Which engine to get?
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69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears.... |
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01-04-2013, 07:29 PM | #9 | |
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Re: Which engine to get?
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67 GMC K1500 Custom- 305V6 SM420, PTO, Ram Assist, yellow (the outcast) (project period correct upgrades) 67 GMC C2500 351V6 TH400, AC, PS, PB (can't decide what to do with. Update, decided to keep and will restore ) 86 CHV K30 502 th400, apple red NEW 71 CHV K20 350 SM465, ochre (saved work truck) 71 CHV K20 292 SM465, white, tach, PTO, (future project) 72 CHV K20 350 350th, medium blue (project stocker) 01 CHV K2500hd crew, indigo blue ^3 dont run and the others don't see winter either '86 K30 Cummins "Fireside" thread: http://67-72chevytrucks.com/vboard/s...d.php?t=649649 '71 K20 "get driveable" thread: http://67-72chevytrucks.com/vboard/s...d.php?t=590642 '72 K20 Build Thread: http://67-72chevytrucks.com/vboard/s...=493477&page=6 |
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12-08-2012, 01:34 AM | #10 |
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Re: Which engine to get?
6.0! I have one in my Silverado SS and its great never have a need for more power!
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68 C10 LWB 2/4 drop 406/th400/3.73posi 04 Silverado SS LQ9 6.0/4L65e/4.11posi AWD |
12-08-2012, 01:43 AM | #11 |
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Re: Which engine to get?
I'm partial to the 6.0 myself. We had a Trailblazer SS with the LS2. We loved it! The 5.3 is practically brand new though!
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1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE |
12-08-2012, 04:44 AM | #12 |
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Re: Which engine to get?
leave the burban alone and get your self a honda for a daily driver.
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12-08-2012, 12:43 PM | #13 | |
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Re: Which engine to get?
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1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE |
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12-08-2012, 09:24 AM | #14 |
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Re: Which engine to get?
If I were making the decision for myself, I would buy a Holley projection and a gear vendors overdrive for that BB. The new Denali gets maybe 14 on the Highway with the 6.0 and multi speed electronic overdrive.
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12-08-2012, 09:40 AM | #15 |
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Re: Which engine to get?
I went with the original 402 and built a .030 over hyd roller motor. I will be using the fast injection. I'm hoping for 14-16 mpg with my 4l80e and 3.73 gears but with 460-500 hp. I could have done the whole 468-496 I just thought it would be cool to make the 402 so people could see the potential they have due to the superior heads flow and strenght. I have set the engine up for NOS if need be but i'll have to change my fuel injection if I go that route. If I was set on swapping I would do the 6.0 with the overdrive.
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NAME: TRAVIS TRUCK: BRUISER 71 C/10 SWB 3.5/5" drop 4.11 GEARS. F.A.S.T. BBC 408 496hp/479ft/lb JAKES 4L80E TCI TCU PTC 10.5" 2800 STALL My build thread: http://67-72chevytrucks.com/vboard/s...30#post5779530 |
12-08-2012, 09:49 AM | #16 |
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Re: Which engine to get?
No matter what engine you decide on for fuel mileage you will need a OD trans. You could do the trans now with the BB just to see how much better the mileage would be. IMOP
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James 63 GMC V6 4speed carryall 65 chevy swb bbw V8 auto 68 K20 327/4 speed, buddy buckets 2002 GMC CC Dually Duramax 64 GMC lwb 3/4 V6 4speed SOLD 66 GMC swb bbw buddy buckets SOLD IG duallyjams The only thing that stays the same is constant change! |
12-08-2012, 01:10 PM | #17 |
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Re: Which engine to get?
If you're doing this for mileage/money then find a 5.3/4l60e combo for about $1-1.5K. Make sure it is complete with all the accessories and wiring. All the ancillaries will add up.
All the things needed to get it done seem overwhelming at first but knock them out one at a time. All the guys on here will help you through it!!!! Think about this though....commuting in a car that gets 6-9 mpg will cost a fortune in gas. Buying a commuter or car that gets a modest 20mpg will save you a few thousand dollars in a years time.... It may be time for cheap commuter/import. With an LS swap you might get close to 15-18mpg (maybe 20?).... This is the route I'm gonna try with my C10 LS 5.3... The thought of a cheap commuter/import gives me the shivers.
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1972 K20 Suburban 5.7/700r4/NP205 Dana 44/H052 Sold 1972 C10 5.3L/4L60E 12bolt 5Lug - Sold 1971 K5 Blazer 6.0L LQ9 4L60E NP205 Dana 44/H052!!! 1970 K3500 1ton CrewCab 8.1L/Allison1000/NP205 Dana 60/14B!!!! - Sold 1984 K10 SWB 7.4L/4L80e/NP208 Corp 10/12 bolt Sold 1988 V30 CCLB 7.4L/TH400/NP205/Dana 60/Dana 70/3.73!!! (Sold) 2003 K2500HD 8.1/Allison1000/NP263 |
12-08-2012, 07:58 PM | #18 |
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Re: Which engine to get?
I think this comes down to money vs. goal. It seems you are considering 2 choices that both have their drawbacks (i.e. "New" 5.3, but with a TH350 - and - 70K 6.0, but with an o/d trans in the deal). Between the two, I'd choose the 6.0 simply because a built TH350 is, well, still just a built TH350. Barely 3/4 tonner big block (or LS) material, even if built. And it won't help your gas mileage at all as it has the exact same gearing as your current trans (i.e. ANY mpg improvement would be due to the 5.3 replacing the 402 only).
So, have you considered adding only an o/d trans to your 402/3.54 combo? You keep the originality, keep the highway gears, get an o/d trans, and keep the born-with torque of the 402. Now, having said that, you will not see as much of an mpg gain as an LS or LQ, but, the money you save by keeping the original motor would pay for gas for a long time... However, if your heart is set on a modern motor conversion, I believe I'd scrap both of your options and look for a relatively low mileage 5.3+o/d trans combo and go from there. While a 6.0 is nice, if your goal is mpg improvement, you're swimmin against the stream with a 6.0 (vs. 5.3) or, for that matter, a TH350 (vs any o/d trans). If the two motors mentioned are your ONLY options, I'd choose the 6.0+o/d combo, avoiding the TH350 like the plague. It's a good trans, but if your goal is improved mpg, it won't help much in the long run. And if you're always going up hill, well, mileage will suck in any combo. |
12-08-2012, 09:53 PM | #19 |
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Re: Which engine to get?
Hey guys! Thank you all for your opinions and advice thus far! It is nice being able to bounce some ideas off knowledgeable people. I live that everyone is approaching this from different angles and perspectives. Couple of things:
I love originality, but I'm trying to be realistic with this suburban. Even with a tune I truly believe the 402 is going to be a gas hog. I didn't really care When we lived in Texas (I generally got 10-12 mpg), but now that we are in California I'm having to actually think about gas mileage. I drove the burb daily when we first got here for a couple of months. With just driving around town taking kids to school and running errands and such I was getting about 6-8 mpg, spending about 150 a week on gas. I can't keep doing that. So the main idea behind the swap is to turn it into a daily driver again. The kids love it (they call it the "broooom broooom" because it's kinda loud) and I would love to get rid of another vehicle and pay some bills off. With that said, if I can't make it an easy to run daily driver with decent gas mileage then I will be forced to sell it, which I really don't want to do. I initially was going towards a 5.3 w o/d from a junkyard, but for one with 80k they want around 2500, plus all the other expenses like harness and PCM program. I liked the low mileage 5.3, but wasn't in love with the th350 combo on it. I thought about doing the 5.3 to my th400, but again, no overdrive. I was only interested in the 6.0 combo because I was concerned about the weight of the 3/4 ton burb killing the mpg and being a slug with the 5.3. I thought maybe the 6.0 torque would offset the potential mpg loss of the 5.3, creating a wash between the two. Adding an overdrive tranny to the big block ends up costing a little less than an engine swap, but i would still end up needing to tune the engine better, and potentially still not getting much mpg improvement. I thought about doing a fuel injection system on the 402, but they are expensive. I thought about used 454 tbi, but even those are getting more expensive. I even considered a DIY fuel injection system. Seems simple enough, but somehow I don't see it being that simple. If I do an engine swap I can sell the 402 and tranny and stands and recoup some of my expenditure on the swap. Geary's 5600, what is the going price for a lower mileage 5.3 with overdrive combo with PCM, harness, pedal, etc in your area? Say about 70k miles, but no more than 100k? Thanks for the responses so far guys! I appreciate them! Shawn Posted via Mobile Device
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1972 C20 Suburban- Big Blue Betty '56 Chevy Bel Air Sedan- Frame up Restoration -What would you attempt to achieve if you knew you could not fail?- -I Refuse To Tiptoe Through Life, Only To Arrive Safely At Death's Door- R.I.P. EAST SIDE LOW LIFE |
12-08-2012, 10:29 PM | #20 |
Fabricate till you "puke"
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Re: Which engine to get?
If you have the time to part the truck, you will be ahead of the game purchased a complete"wrecked' 2000 GMC.4wd, with a good running 5.3 (130,000 rounds). I gave 1700 for the old truck, & 80 bones to tow it home....after all the smoke cleared(parts sold ,ect), I have $80 in a good running 5.3/all accseries/harness /computer....pluss a few parts for my 02 Silverado crazyL
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69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears.... |
12-08-2012, 10:40 PM | #21 |
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Re: Which engine to get?
I bought an 04 5.3l/4l60e/computer/harness with 30k for 800 in Texas last year
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"To speak of the art of one loom, the art of one river, the art of one tractor, or the art of one automobile is not preposterous; it is to point to the size and importance of the gap between general knowledge and situated knowledge" - James C. Scott 1969 C10 - http://67-72chevytrucks.com/vboard/s...d.php?t=492064 1930 Tudor Sedan |
12-09-2012, 12:10 AM | #22 |
Fabricate till you "puke"
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Re: Which engine to get?
The 6 liter engines, seem to command the big bucks.....as shown, you can pick that 5.3, for a lot better price. Your truck.....your call, do what makes you happyThat is the way I do it Big fun, crazyl
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69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears.... |
12-09-2012, 02:37 PM | #23 |
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Re: Which engine to get?
You should in no way pay more than $1500 for a 5.3/4l60e combo with all the wiring and accessories. At least, I wouldn't. I got my set up for $1300 local. There are guys who got theirs cheaper but I figured I could stay local, get a little guarantee from the salvage yard, etc.
I just can't imagine being disappointed with this combo once it's up and running. If I remember correctly, LS1tech.com shows a lot of guys getting great numbers and cost starting with 5.3l and switching heads/cams/tunes. The 6.0L is not an absolute and neither is the LS1/LS2....
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1972 K20 Suburban 5.7/700r4/NP205 Dana 44/H052 Sold 1972 C10 5.3L/4L60E 12bolt 5Lug - Sold 1971 K5 Blazer 6.0L LQ9 4L60E NP205 Dana 44/H052!!! 1970 K3500 1ton CrewCab 8.1L/Allison1000/NP205 Dana 60/14B!!!! - Sold 1984 K10 SWB 7.4L/4L80e/NP208 Corp 10/12 bolt Sold 1988 V30 CCLB 7.4L/TH400/NP205/Dana 60/Dana 70/3.73!!! (Sold) 2003 K2500HD 8.1/Allison1000/NP263 |
12-09-2012, 03:35 PM | #24 |
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Re: Which engine to get?
We sell the 5.3/ 4l60 combo for 1200-2000 depending on miles..
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MY BUILD THREAD http://67-72chevytrucks.com/vboard/s...d.php?t=423629 1969 custom/10 swb--SOLD 1968 swb 50th anniv.--SOLD 1967 camaro ss/rs..LS-6-speed, 16-year long project 1956 chevy nomad 1955 chevy 210 2-dr sedan 1978 el-camino ss 1-owner |
12-09-2012, 03:41 PM | #25 |
Hittin E-Z Street on Mud Tires
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Re: Which engine to get?
Stay away from all 2007+ 5.3L engines. They have AFM and are having a lot of issues with oil consumption and the 4 AFM lifters going bad... I'd stick with the 06 and older 5.3L.
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Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! |
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