new drive train? LS? LT? Tecumseh?

[bigdumbhick]

I have a 71 GMC with a non-original 305 that is on its last legs. The th350 Trans leaks like a gunshot victim due to hardened seals. I am currently searching for a replacement motor and someone who can swap it out for me.

What can I drop in this bare bones farm truck to restore it to dependable transportation? Its an ugly. beat to crap, rusted out bed and cab corners, no P/S, P/B, or A/C truck that is used for truck stuff - Hauling a scoop of gravel or topsoil, firewood, occasionally trips to the dump...and I occasionally like to camp In it. Throw an air mattress in the back and a pop-up canopy over the bed. Occassionally I use it as a backup vehicle for my 60mile RT work commute.

I am in NC. What is my easiest and cheapest solution for returning my truck to dependable transportation?making it road worthy/ The rebuild cost for the th350 is $1500-$2000. A crate 350 is about another $2000. With labor I'm looking at $5k-$6k and I'm not sure I want to invest $6k into a $1500 truck.

EDIT: I should point out that I do not have the skill, space, tools, health, or time to swap out an engine or transmission. I'm going to have to pay someone to do that

[wesmigletz]

5-6 years ago, I would have recommended a GM crate engine and a rebuild of your trans. IMHO, GM priced themselves out of the replacement engine market. With price being an issue, I would try to find a low mile 96+ vortec 350 off of FB or Craigslist, get your trans rebuilt, and install the later 350 with a performer intake and a Qjet, The fuel injected engines don't seem to wear as much as the older carbureted engines. A vortec 350 with 100K miles might give you another 100K.

[dmjlambert]

Your more-beautiful-than-you-think truck will be worth having the engine and transmission overhauled. It's not a $1500 truck. I bought my truck out of the field where it croaked and the first owner parked it 37 years ago. Interesting how it was a hideous mess just a couple years ago, and after having done nothing to the outside and getting the engine and transmission overhauled and seat re-covered, it is a beauty now. I occasionally wash the windows. I get complements and thumbs up all the time and it makes me smile to drive it. I don't have any current plans to do anything to the body, I kind of like it with the body and paint job by a collaboration between Chevy, Time, and God, it took many years to get it just right. My suggestion is you don't need power brakes and steering, but go ahead and add A/C and put a bluetooth amp and speakers under the seat, and drive it a lot.

[truckster]

I built an L31 Vortec for my Blazer and I would go that route again. Old-school looks with more modern reliability. There are a few things you'll have to change, like the flex plate, but it's a pretty easy installation.

[MidLifer]

Gen III Vortec, 4.8/5.3/6.0 - they are plentiful and cheap, have a 300K duty cycle and there is literally reams of online information about how to do the swap. In fact there's a sub forum on this site (under the engines forum) dedicated to it.

I did a 6.0/4L80e in my now-sold 71 C10 and almost bone stock with just a cold air intake and a ECM tune it had all the power I ever wanted. Now doing a 5.3 in a non-Chevy project.

You can do this all-in for 3-5K depending on how extravagant vs. cheap you want to get. Best thing is to find a donor vehicle so you get all the parts you need and you can get some money back by parting/scrapping it. Look for a pre-2007 Suburban, Tahoe or Avalanche, those usually got less beat-up than the work trucks. Or if you want 2WD look for a van. Unless they were neglected or beat on they usually don't need any work done to them.

In 2008 (some 2007s) they started with the DOD, which wasn't a good thing. You can delete that on a Gen IV engine but it's more hassle and the damage has already been done to the inner workings by the time you get it.

[MARKDTN]

Your 305 is a V6? Your transmission price is very high. You can buy a built racing version from Jegs for $1500. If you took it out and took it to the shop I would think less than $500. The Vortec swap is a good idea, but since you have a V6 you don't have the right pulleys. I would look around on Marketplace or similar for somebody putting an Ls in an old Chevy car/truck and selling the engine and transmission. Then you would have all the right brackets and such. You would need V8 engine stands and exhaust manifolds. I love EFI stuff myself. An LS swap would also be very cool if wiring and fuel stuff doesn't bother you.

[LNP]

Originally Posted by bigdumbhick

I have a 71 GMC with a non-original 305 that is on its last legs. The th350 Trans leaks like a gunshot victim due to hardened seals. I am currently searching for a replacement motor and someone who can swap it out for me.

What can I drop in this bare bones farm truck to restore it to dependable transportation? Its an ugly. beat to crap, rusted out bed and cab corners, no P/S, P/B, or A/C truck that is used for truck stuff - Hauling a scoop of gravel or topsoil, firewood, occasionally trips to the dump...and I occasionally like to camp In it. Throw an air mattress in the back and a pop-up canopy over the bed. Occassionally I use it as a backup vehicle for my 60mile RT work commute.

I am in NC. What is my easiest and cheapest solution for returning my truck to dependable transportation?making it road worthy/ The rebuild cost for the th350 is $1500-$2000. A crate 350 is about another $2000. With labor I'm looking at $5k-$6k and I'm not sure I want to invest $6k into a $1500 truck.

I would ask around where you live I'm sure theres mechanics that work in garages for a living that also works on them at home. If you were near me I would do it between $500-$1000.00 plus fluids and any extra part needed. I bought a crate 350 from Jegs for $2100.00. I got the 1987-95 style engine so I could install a 700R4 overdrive trans. I got the trans from a local transmission repair shop for $1550.00. The engine had a 3yr unlimited mileage warranty and the trans had a 3yr 36000 mile warranty.

[bigdumbhick]

Originally Posted by MARKDTN

Your 305 is a V6? Your transmission price is very high. You can buy a built racing version from Jegs for $1500. If you took it out and took it to the shop I would think less than $500. The Vortec swap is a good idea, but since you have a V6 you don't have the right pulleys. I would look around on Marketplace or similar for somebody putting an Ls in an old Chevy car/truck and selling the engine and transmission. Then you would have all the right brackets and such. You would need V8 engine stands and exhaust manifolds. I love EFI stuff myself. An LS swap would also be very cool if wiring and fuel stuff doesn't bother you.

The 305 is a V8

[MARKDTN]

Originally Posted by bigdumbhick

The 305 is a V8

Revised based on that.

Your transmission price is very high. You can buy a built racing version from Jegs for $1500. If you took it out and took it to the shop I would think less than $500. The Vortec swap is a good idea(but forces you into an aftermarket intake). I would look around on Marketplace or similar for somebody putting an LS in an old Chevy car/truck and selling the engine and transmission. I love EFI stuff myself. An LS swap would also be very cool if wiring and fuel stuff doesn't bother you.

[special-K]

Just remember to go with an LS swap you are adding a lot of money for the conversion. It's best, for money sake, to go with a drop-in engine and trans

[LNP]

I didnt use a LS and mine was a drop in engine and trans. Plus I didnt have to deal with the computer and all the wiring. LS also means a intank fuel pump or one of the new high pressure frame mount ones plus a fuel return line. Not that all that is difficult but it does add additional work and money.

[body bolt]

If I was starting from scratch I'd probably do an LS. But like others have said your truck is already set up for something else plus it's all documented in the service manuals. It's much simpler.

[indymachinist]

Sounds like the most practical approach is sticking with a similar SBC and trans like is already in the truck.

LS swap guys always underestimate what it takes to do a swap. Both in the money and time areas. To pull off a well thought out, reliable LS swap is no small undertaking. Ive seen some pretty horrible hack LS installs (even from “shops”) that would make me rather have an old carbed SBC.

This is coming from a perfectionist guy who did his own LS swap. So take it with a grain of salt I guess.

[jumpsoffrock]

Tecumseh all the way!!! lol

[Joyridin]

Personally, considering all the people that are pulling engines to install LS engines, I would look for a 292 6 cylinder. They have a lot of torque, easy to fix, run basically forever, get decent mileage, and you can probably find one for a few hundred bucks.

I would not waste my time on an LS conversion. Lots of time and money and finding one for $800 with 130,000 miles is getting a bit hard these days.

[67 twins]

Originally Posted by Joyridin

Personally, considering all the people that are pulling engines to install LS engines, I would look for a 292 6 cylinder. They have a lot of torque, easy to fix, run basically forever, get decent mileage, and you can probably find one for a few hundred bucks.

I would not waste my time on an LS conversion. Lots of time and money and finding one for $800 with 130,000 miles is getting a bit hard these days.

Hey don't be giving away the secret. You start telling everyone and these 292s are going to get hard to find. Lol

[LNP]

Originally Posted by 67 twins

Hey don't be giving away the secret. You start telling everyone and these 292s are going to get hard to find. Lol

[Palf70Step]

AS mentioned, probably the cheapest would be to put in another small block. Changing to the 6-banger or LS require additional parts and all, while your current engine has everything you need for a replacement small block. Around here you can lots of times find a good small block (and T350) that someone is going to pull out to put in an LS. THat's cheapest way to go, or go with crate engine and redo ur T350.

[MikeB]

Unless you can find someone with a good or rebuildable 350, I'd get the 305 overhauled, and then get the trans leaks fixed.

Or this engine should work for you, and it's probably one of the least expensive engines you'll find:
https://www.jegs.com/i/ATK-Engines/059/VC09/10002/-1

Better yet, if you have a trusted shop nearby, ask them what would be the easiest and cheapest for them to do.

A couple years ago, a friend of mine bought a 350 and TH350 for $1,000. The deal included a carb, distributor, and headers. They came out of a square body truck that I had just sold, so I know the combo had no more than 10K miles on it, and that I had spent at least $3,500 on engine and trans. Literally everything in the engine was new except the block and oil pan. I'm still kicking myself for not buying it.

[kev2809]

being you want the cheaper option, I'd go with a small block.

I LS swapped mine by myself so I didn't have to pay anyone, but it does add up quick. you don't HAVE to find a super low mile engine either. mine had 200k when I pulled it and it runs like a damn top. sits for a few weeks sometimes and still cranks right up and go

[truckster]

Originally Posted by Joyridin

Personally, considering all the people that are pulling engines to install LS engines, I would look for a 292 6 cylinder. They have a lot of torque, easy to fix, run basically forever, get decent mileage, and you can probably find one for a few hundred bucks.

I would not waste my time on an LS conversion. Lots of time and money and finding one for $800 with 130,000 miles is getting a bit hard these days.

A V8 to 292 swap is going to cost a lot more and take a lot more work than a simple SBC swap. Even a Vortec swap is going to be cheaper.

[MikeB]

I think an LS is the last thing the OP needs for his bare bones, rusty farm truck. I say that having built up a late 90s LS1 destined for a 55 Chevy car. I'd estimate the price of parts to be 2-3x the cost of the engine and auto trans (4L60E?). Also it may be hard to find an honest, knowledgeable shop to do the work. And then add another few thousand for labor.

[Joyridin]

Originally Posted by truckster

A V8 to 292 swap is going to cost a lot more and take a lot more work than a simple SBC swap. Even a Vortec swap is going to be cheaper.

How? The truck has no P/S, P/B, or A/C. The only think I am not sure about is if the transmission will bolt up, but he stated he needed a trans also. As I mentioned, you can probably find one of these for peanuts sitting around that was pulled for an LS swap. Throwing in a used SBC would be cheap, but he never mentioned that option. He was talking crate engine and a 292 isn't anywhere near that.

[MikeB]

I'm not saying a 292 would be a bad option. In fact, a fresh one would be a cool upgrade to an ailing 305. But extra work will be required. Here are some of the things that will need to be done based on my experience converting from a 250-six/manual to 350/TH350 in an 82 C10:

• Some electrical wires will need to be lengthened, some shortened.
• Fuel line mods.
• Different radiator hoses and possibly heater hoses.
• Alternator belt, pulley, and bracket (unless they come with the 292)
• Frame-mounted motor mount brackets relocated. (I'm not sure is this needs to be done on a 71.)
• New exhaust down pipe.
• Some mods to kickdown linkage and modulator hard line/hose.
• Throttle cable on 292 six will probably need to be longer.
• Will have to get the 292 mounted so trans is in the same place longitudinally.

[68bowtie]

Originally Posted by bigdumbhick

The 305 is a V8

There was a 305 v6 in early (1967) gmc’s.