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#1 |
Registered User
Join Date: Sep 2015
Location: santa fe nm
Posts: 6
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Engine Swap?
Hi Guys,
I have a 1972 GMC Sierra Grande K2500 Camper Special. New original white over bronze paint looks great. Its got a leaky crate engine, but most of the truck is rust free original, or 98% restored. I could use some advice on doing an engine swap, or at least a rebuild. I'm of two minds here. First choice would be an LS with a new trans. Second choice would be a "new" crate engine. Third choice would be to rebuild the crate I've got. Of course, cost is a factor overall. Some of my buddies argue that the truck is so original (I'm only the second owner) that I should keep it as close to original as possible. However, I'm leaning towards at least a new intake and a computer driven fuel injection system to improve reliability and fuel milage. Any thoughts would be appreciated. Tomaso |
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#2 | |
Registered User
Join Date: Mar 2007
Location: Oakland, Ca
Posts: 1,382
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Re: Engine Swap?
Quote:
![]() it's my opinion that the LS swaps are overdone. They're F'n everywhere. If it were me I'd pull your existing engine, rebuild it and upgrade to the Edelbrock Pro Flo 4 MPFI system. I just installed one on my 383 and I love it. I doubt fuel injection will really help with mileage that much, however. Remember you're driving a brick down the road ![]() Now i'm sure some LS guy will come on here claiming he gets 20mpg. So if mileage is really your goal maybe thats the route for you. |
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#3 |
Registered User
Join Date: Dec 2012
Location: Temple City
Posts: 3,590
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Re: Engine Swap?
A 95+ Vortec engine, can be disguised quite well. Offer better power then a gen 1 sbc, and the roller cam is not effected by lack of zinc like traditional flat tappets. With general parts store oils that is.
Bowtie Vortec heads are a respectable 180cc, and have both valve cover mounts. Mercruiser has Vortec Q-jet iron manifolds. Easily found on ebay among other places. So to 99% of gear heads it would appear stock, but with a extra 50 hp/tq. With the same driveability. |
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#4 |
Post Whore
![]() ![]() Join Date: May 2015
Location: Alabama
Posts: 14,639
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Re: Engine Swap?
normally i would be in for the LS swap
but since you factored in cost limits and the fact you have a K truck...there would be considerable xtra costs to do the LS/trans swap.... build what you got....
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Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver Last edited by mongocanfly; 02-14-2021 at 10:00 AM. |
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#5 |
Senior Member
![]() Join Date: Jan 2001
Location: Orem, Utah
Posts: 7,911
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Re: Engine Swap?
I'm a fan of the L31 Vortec. I just put one in my 72 Blazer.
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I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson |
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#6 |
Registered User
Join Date: Jun 2015
Location: Carlos MN
Posts: 2,045
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Re: Engine Swap?
I would pull the "leaky" and take it to a machine shop to see what you have. If its toast a new crate would be the least expensive route. If your current crate is sound block and head wise it's pretty easy to throw in a 383 stroker kit. If you go that route make sure your heads don't choke it off.
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#7 |
Registered User
Join Date: Feb 2013
Location: central California
Posts: 2,736
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Re: Engine Swap?
What else besides the leaks seem to be the problem with the engine you have? Is it at least worth a compression test? I dunno I've seen to many leaky motors that seem to run just fine. Sometimes a good cleaning and re-sealing, along with a new timing chain, oil pump and brass freeze plugs (if doesn't have them already) fix 'em up pretty good. I have a 283 like that. Incredibly, its been going for so long now that I cleaned and re-painted it again just a little while back. It was supposed to be freshly rebuilt when I bought it 35 years ago and I've never had to pull a head off of it yet.
Last edited by AcampoDave; 02-14-2021 at 08:59 PM. |
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#8 | |
Senior Member
![]() Join Date: Dec 2011
Location: Moraga, CA
Posts: 812
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Re: Engine Swap?
Lowest cost and easiest is probably a crate engine -- cost depends on power level.
For me the most fun is a rebuild. I had fun rebuilding mine to the '70 Corvette/Camaro Z-28 specs for '70. But in the future, not sure what I'd do because my favorite machine shop (Morgan's in Walnut Creek) just closed this summer. (SeventyOne: where would you go for machine work in the East Bay Area?) If you want a technical challenge and the most power then go with the LS, but that will cost time and money. On the fuel mileage thing, if you calculate how many miles you drive per year, your fuel cost, and so on, the payback time is pretty long. So figure out how much that is worth to you financially as well as bragging rights. ![]() Quote:
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(Very) Slow-Going Build Thread: Stock 1970 Short Step with Stock 1970 LT-1 http://67-72chevytrucks.com/vboard/s...d.php?t=567340 |
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#9 |
Registered User
Join Date: Oct 2013
Location: Maine
Posts: 2,357
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Re: Engine Swap?
I was thinking it was a 402 and you should keep it. If it's a 350 then any crate engine will do.
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#10 |
Registered User
Join Date: Dec 1999
Location: Austin, TX, USA
Posts: 7,717
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Re: Engine Swap?
I agree that the LS thing is overdone and much more expensice than you'd think starting off with an inexpensive motor.
Some good suggestions above about checking out your existing motor. We pulled the 350 from my kids Jimmy project and tore it down to the shortblock. Added a Z/28 oil pump, 204/214 @ .050 "RV" cam with double roller chain, an Edelbrock Performer intake under a JET Stage II Q-jet, HEI distributor, and 2 1/2" Corvette Rams Horns. Significant increase in performance. Added a set of "Chevrolet" raised script valve covers and shot the whole thing orange including the intake with Summit Urethane Hugger Orange. It looks mostly stock, sounds mostly stock and runs great. If I had a little more money to spend on a similar project would have gone to a 383 and the Vortec dual bolt patter heads to use the older style valve covers and intake manifold along with a 214 to 218 @ .050 cam. The FI is really cool but for me I would want trans control if I converted and that doubles the price. The Q-jet works great when they are in good shape.
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#11 |
Registered User
Join Date: May 2016
Location: Henderson NC
Posts: 975
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Re: Engine Swap?
I understand wanting to keep it looking original and I was the same way but now after 5 years and no sign of a leak I would trade my center bolt valve covers for the old style if you paid me to swap.
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