Hi everyone. New to the forum and looking for help/ advice.

I have a 1985 trans Am that is automatic and has a 305.
Now the motor has over 300,000 miles on it and does not run right do to the carb missing half the hook ups and is all stock.

Now I want to rebuild the 305 and I'm on a budget and I do not want to hear "stick a 350 in it". I"m not looking to build a world beater. Just a small block with some snort. I just want to use what I've got.

What I want to do is pull the motor and transmission, rebuild the motor without a computerized carb. Should I stick to computerized or not?
The other thing I want to do is swap the transmission with a new 4 speed auto and use a hammer shifter or something similar.
Along with a cam, what cam should i use?
I'm just asking for thoughts on my plan and tips and things to look out for when doing this rebuild. Thanks!

 

Question- are you staring with an LG4 lo-po 305 or an L69 HO 305? The pea-shooter exhaust on the LG4 has to go- all of it from the manifolds to the tailpipes if you want any kind of performance potential out of the motor at all. The L69 you can get away with the (larger) stock exhaust that it comes with for a mild performance application, assuming the cat isn't melted or damaged in some way.

I'll point out that you can buy a NEW 250HP GM 350 universal replacement engine that will BOLT IN PLACE of your 305 for about $1500. And it'll feel like you bolted a second engine under the hood compared to the 305. It'll even play nice with your computer controled QJet/HEI system, if you decide to fix them and use them for this project.

Now you MAY be able to do a mild performance build on the 305 for less money, but that depends on what work it needs. If it's just an overbore, pistons, rings, polish the crank journals and slap new bearings and a cam in it, yeah, you can do it for cheaper than the 350. If there is anything more that it needs, however.... the cost starts making that 350 more attractive by the second.

Assuming that's all good, you can go with a Summit house brand K1102 cam & lifters kit, flattop pistons and an entry-level aftermarket 4bbl intake (with EGR capabilities recommended if you are keeping the computer controlled stuff). If you're willing to add shortie headers, 3" y-pipe, cat (if you need to pass emissions) and 3" cat-back exhaust, you will have a fairly stout 305 for a daily driver.

Just realize that exhaust is going to cost you the better part of a grand when you add it all up. That's why I mentioned reusing the factory exhaust IF you have an original L69 car. If you have an LG4 car, forget it, you're buying the exhaust, period.

 

Sorry i'm learning all this stuff about these cars. Whats the difference between the Lg4 and the L69 and how can i tell the difference?
Now with the universal 350 would i have a problem with the hood or would it fit pretty close to perfect?

A lot of the engine work is unknown at this point until i pull it and tear it down. I'm trying get ideas and get as much info as i can get until I get to it which hasnt been easy with work and etc. But other wise besides the carb missing half of the parts the motor its self is a strong runner and i know it has potential to have some snort to it.

Now would you recommend staying with computerized or just getting rid of it? Id rather get rid of it but I dont know much about it and it would seem that it would be an ''easier'' root because the car is setup to run it. And also emissions is not required so i planed to cut the cat out and straight pipe or a performance exhaust system which i know will not be cheap. And as of now there is an exhaust leak and i think its up by the headers or exhaust manifold. Wont be able to pin point it till its torn apart.

 

A 350 is exactly the same external dimensions as a 305. No fitment problems whatsoever. If you buy an aftermarket intake you can run into hood clearance problems, but all the accessories, exhaust, etc. will bolt right on and be in exactly the same place.

Deciding whether to keep the CC-QJet system comes down to whether you need it all on there to pass visual emissions check (a deal-breaker in some areas of the country) and just how badly the system is hacked up to begin with. A non-computer-controlled QJet and HEI distributor will bolt right in place of the computer controlled units, which makes the conversion away from computer control very simple and potentially cheap to do- a significant attraction on a car that's been badly hacked up by POs.