Posting this here, because the other section might not be the right place

So I'm new here, been surfing the forums for a couple days and decided to register as the forum as a whole seems very knowlegeable and helpful.

I have a few questions regarding my 1988 Pontiac Firebird (formula) and it's tired old 305. Just so the details are available, I own a 1988 Pontiac Firebird with a TBI 305 and a 5-speed manual behind it.

I just purchased this car from a gentleman who claims the motor has never been rebuilt. True or not, it's seen 175k miles and blows a good deal of smoke, and there's no doubt in my mind that the heads are toast and the rings are probably worse. Chances are the cylinder taper is pretty rough as well, so if it gets rebuilt it will need to be machined (no ghetto garage honing for me ).

My questions are as follows. I'm looking for a quick, painless way to get her running acceptably again. My two options so far are 1) Rebuilding the 305 or 2) Throwing a 350 in it. Rebuilding the 305 would be simpler (already have the motor, TBI wouldn't need to be junked, proficient in that sort of thing) but it's fraught with potential problems. Crank could be a mess, cylinders might be .60 over...etc etc.

Being a recent Ford convert and a novice mechanic, there's quite a bit about the 350 swap I don't yet understand. The engine in it now is TBI. Will the computer be able to handle the extra 50 cubes or am I better off carbing it? TPI is a hassle to wire and I'm terrible with electronics, so that's out. Thankfully it is a stick shift, so if carbing is the only answer, it wont be too difficult. If I swap the 350 in and it's from an auto, will I need to use my 305's flywheel? How can I be sure that it will be balanced correctly (or close enough to not matter)?

What sort of 350 should I be looking for? Roller or flat tappet, neither matter to me, and I'm not looking to make a monster out of it so 2-bolt main is fine. What I'm really hunting for is compatibility. Cheap and uncomplicated has always been what I've liked about GM, and it's what I'm looking for now.

Do any of you gentlemen think I'd still be better off keeping the 305? I understand with better heads and a half decent exhaust you can actually get some decent numbers out of them.

Any answers or helpful tips would be much appreciated. I've always been a GM man at heart, I'd like to finally have a vehicle I can stick with and not end up frustrated.

 

Welcome aboard thirdgen.org.

Your assessment of the condition of the engine is probably way too far on the gloom & doom side. Small block Chevys smoke because the valve stem seals are a poor design and made of a material that hardens and cracks with normal use.

On the other hand, the cylinders are likely in great shape, assuming the engine has had decently regular oil changes. So, replacing valve stem seals, which can be done with the heads still on the engine and the engine in the car, are probably all it needs.

If, on the other hand, it really is worn out, or you just want a project, rebuilding a 305 is about the worst use of funds possible. You can buy and rebuild a 350 for little more than rebuilding the 305 would cost, and the power potential, without a substantial effect on economy, is much greater with the 350.

An '87-up block for roller lifters would be the best core choice. If you do that, your 305 flywheel will work just fine - flywheels are "spec" balanced, not balanced to a particular engine or even a particular displacement. You can even use a truck 350 block '87-up that didn't come with roller lifters from the factory, as most of those blocks were machined for the roller lifters. Just take them out of the 305 and put them in the 350.

There is a sticky in the top section of the TBI forum that details a budget 350 swap.

 

If you want more power, swap to a 5.7, if you dont care and just want OE power and economy, rebuild/replace with a crate motor.

 

I would not reccomend rebuilding a 305, its not worth it. you would have to pull the 305 out and completely take it apart. It would be alot easier for you to rebuild a 350 and drop it in. Also if you did a 350 swap you would be able to drive your car while rebuilding the engine.

 

Lots of great responses, thanks for all of your input. I didn't know about the valve stem seals...I'm going to try to fix that right away! If that works, I'll be very impressed.

my biggest concern with swapping in a 350 is eating up the tranny. I've heard many "gloom and doom" so-to-speak tales of T5's giving up under load from slightly improved 305's, let alone 350 torque.

 

It's shock more than torque that kills T5's. Many members have run and even raced T5's behind 350's, 383's, and 400's. The key is not to try high-RPM clutch-dumps or speed shifting.

But, the oil burning issue is probably the valve stem seals. The oil getting down the valve stems and into the combustion chamber has probably protected the cylinder walls from wear. . .