Engine Swap?

[Tomaso]

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

[SeventyOne]

Originally Posted by Tomaso

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

This is so subjective and personal to each person...BUT I'll throw out my (likely unpopular) opinion because you asked!

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.

[Ziegelsteinfaust]

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.

[mongocanfly]

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....

[truckster]

I'm a fan of the L31 Vortec. I just put one in my 72 Blazer.

[LS short box]

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.

[AcampoDave]

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.

[mattfranklin]

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.

Originally Posted by Tomaso

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

[cadillac_al]

I was thinking it was a 402 and you should keep it. If it's a 350 then any crate engine will do.

[Mike C]

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.

[garyd1961]

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.