I have a 87 firebird with a 305 carbureted. I took it too a shop to have it rebuilt and they only rebuilt the top end and put a bigger can in it. They put all the new seals and gaskets but gave me lots of issues. It now has a knock in the bottom end and misfires, they put the incorrect intake manifold on it and drilled it to put it on so another thing I will have to change. I have a feeling that is why it misfires. Just giving extra info to get a better idea of what's going on with the motor. I'm curious as to what it will cost to change the rings and bearings at a shop to a full bottom end rebuild. I have found a reputable shop to do the work. I know quite a few people that go to this shop and get good work done. Please don't say just swap the motor, I would like to know the cost to fix the motor since it's got work done to it already. Thank you in advance any feedback is appreciated.

 

Whatever cost of bearings and rings are plus machine and labor. All depends what you buy

If cylinders arent in good shape its gonna need bored and honed and new pistons. Assembly balanced. Crank polished, maybe even turned if not in good shape.

Mains checked and possibly honed if out of spec. If spun bearing they may have to machine caps some. Hopefully not align honed

But usually boring cylinder out is 300-350 ish.
Balancing assembly 200-300
Resurface block deck 100-150
Clean everything hot tank etc 100 ish
Assembly 300-350 ish maybe more?
If align hone and fix caps, 300-400

It all adds up alot depending what all needs done.

 

$800+

305s aren't worth rebuilding. 350s aren't really worth rebuilding.

 

Thanks for all the info very informative. It's not as bad as I was thinking it would be I plan on when I get my taxes back having it done then. The shop allows around like 500-750 initial deposit to start work which I can come up with and tax money I can use to pay the rest. I'm going for more of a daily then performance but had the cam put in to gain a little power. So sticking with 305 till I want more performance.

Sorry for the lengthy response, but thanks

 

If things somewhat check out ok and its not a high performance spec rebuild then might be simple as cleaning everything off, polish crank, slap in new bearings, and quick hone cylinders and slap in new rings on same pistons. Wire wheel clean deck and slap heads back on with gaskets and hope everything seals

That be relatively cheap. Could almost do it in your garage with a ball hone drill attachment lol

 

That's the most common thing I hear but sourcing a 350 or 383 where I am at can be difficult, at least for a fair price plus I would have to have a shop install it. I lack a garage and engine hoist so would be a very difficult thing to do in my case.

 

​​​​​​I could try to take it to a friends garage and take it apart and do it. It just developed the knock and I haven't ran it since. I think after the top was redone it just put to much stress on the lower end.

 

The install for a 305 is the same as a 350. A few parts may need to be changed, but 30 years later those parts usually should be changed anyway. Look into crate engines. GM offers a couple different 350 crate engines for under $2k.

The big problem with the 305 is that it's false economy. Generally speaking costs for a 350 are going to be the same or less than a 305. As much as many people don't want to hear a suggestion to swap to a different engine, the suggestion is intended to save you money and frustration in the long run. As you said, you don't want to give up on your 305 because you've already invested heavily into the 305. Investing even more, only to have potential issues later on... Know what I mean? Good luck, either way.

 

Yeah I noticed most parts generally the same but the actual cost is cheaper for a crate 350. I was thinking maybe a 383 with heads that needs like intake, distributor etc because I can use my carburetor and anything transferable. Input is appreciated for sure.

 

I agree finding a better base to build is recommended

For a full proper machine shop treatment on a 305 block, you have to be doing it for 1 of 2 reasons. 1: to keep car original. 2: you want to be different and stay with the 305 and Power is not the goal.

Thats fine in either case.

 

When you add in all the extra labor to do a proper rebuild, I'm always suggesting to buy a crate engine. Even a stock replacement engine has all the required machine work done.

You can always replace the camshaft that comes with the new engine for something better. If you already have a set of good heads then buy a shortblock.