OK, Here is my next project. My 83 TA now has been completely restored
painted new interior. Now its time to rebuild or swap the engine.
I have a 305 with Q-jet carb all stock. Really doesn't move. Smokes on start up,
has 154,000 miles. With a $3000.00 budget whats the best option. Rebuild the 305 or purchase a crate motor. I would like to keep the carb. and the auto
700R4 trans. I want to just bolt it in and go turn key but a little more horsepower.
Maybe a 383 stroker? Any ideas, should I attempt to do the work myself.
Thanks for everyones help,
Al
New Haven ,CT

 

What is your HP goal? an upgraded 305 and mild 350 can run just fine on the stock carb. Add some headers, exhaust and maybe a better manifold and you will be in better shape.

 

Rebuild will likely be cheaper unless you buy a crate motor that has roughly the same specs as the 305. If you go for a 383 then you'll likely need headers, new exhaust, etc which will add to costs. Especially if you don't want to do the work yourself.

 

Buy a GM crate L31 for about $2000 and an Edelbrock Performer Vortec manifold, and you're rockin and rollin with 100 extra hp

See sig below for the performance potential of such a simple swap.

 

Thanks Guys I will think about it.

 

Cost of a rebuild depends on how much of a rebuild it needs.

The cylinders probably need to be bored out which will require new oversized pistons. Camshaft should be replaced, timing chain etc. Deck should be milled to make sure it's flat. Heads should be rebuilt as the seats are probably worn, guides worn, springs weak etc.

Cost of parts isn't going to put you over budget but cost of labor to get all the machine shop work done can easily eat up your budget.

As for a replacement, even a bone stock factory replacement engine will be far better plus will come with a warranty. You can also go up from there with a lot of other performance option engines plus they should all come with a warranty. Final cost may be slightly higher than your budget but if you screw up the rebuild, all the money invested to do the rebuild is wasted.

When I got my race engine built, I had the machine shop do the entire rotating assembly. I did the cam, installed the heads etc but I don't have all the proper tooling to make sure the bottom end is done 100% correctly. Even my heads were rebuilt by a local engine builder. Needed seats ground, new guides and new valves.

That's the difference between building an engine and assembling an engine. Anyone can buy a bunch of parts and start replacing them but there are so many tolerances that need to be checked during assembly that a rebuild may only last 100 miles when you'd expect it to last at least 100,000+ miles.

A replacement 305 and 350 should cost the same. A 383 may also be the same price or slightly higher since building a 383 isn't as exotic as it was 30+ years ago.

If you want to go the least expensive route, you can slap the engine together with new bearings, gaskets, rings and cross your fingers that it will last which it probably won't.

 

Thanks a lot I found a 350 at Summit for
2,300. Just needs intake carb.and few other things.
My 83 Trans Am is mint inside and out has new paint job.
Do you think swapping the motor will affect value
not numbers matching.
Thanks,
Al

 

AGREED! Swap the weenie stock Vortec cam and a Alex spring kit and you could have 150+ HP

 

No. Absolutely not.

"Numbers matching" matters when the car is something memorable and desirable in the first place. The 305 is neither.

If the car was "special" in some way from the factory ("Anniversary Edition, "Recaro", L69, etc.) AND had VERY low miles, AND was all still in factory like-new condition (factory paint, factory interior, etc. etc.) there might MAYBE be some small residual value in "numbers matching".

You don't say exactly of course, but if this is just yerbasic LG4 car with like 200,000 miles on it, then especially with all that other stuff NOT factory anymore, it won't ever have "that kind" of value.

The L31 suggestion is probably the cheeeeeeeepest eeeeeeezyest route from getting smoked by minivans to at least not being an embarrassment anymore.

 

What's done is done , and the car itself is already restored and painted per your first post so it don't much matter here , but , you did it kinda backwards . The very first thing a car restorer should do is the mechanical restoration , have the running gear and drivetrain totally finished , and then and only then work on cosmetics as the last part of the restoration .

It's like refinishing a room in your house in that there is a logical order in which to do the tasks , ceiling first , walls second , floor last .