I am picking up a mint 1986 WS6 Trans Am in a month in a half. The guys wife passed on 11 years ago and it has sat and never ran for all these years. I would like to know what I can do to spruce up the existing 305 (if I get it running) since I don't have the money for a sbc 350 and and a T56 I know the stock T5 can handle a completely stock 350 aslong as you don't miss shift but I don't even want to take the risk. What would you recommend I can do to make this car have a bit more power, I am not looking for crazy fast, but just a bit faster then current, I had a 305 H.O. Camaro and it moved pretty good, and honestly I was sort of happy with it, gas wise and it was fun to drive.. Please help guys I will make sure to make a thread regarding my project.

 

I did some research but could not find out what gear ratio it has and if its a posi.
https://www.thirdgen.org/1986-pontiac-firebird

 

The transmission currently is a manual Borg Warner T - 5, 5 Speed Trans.

All new front brakes + rear axle redone ,new lifetime radiator ,headers,center-force dual friction clutch and pressure plate ,B&M short trow shifter, polyurethane bushings on transmission and torque arm ,etc ,etc...needs starter,not running, solid project car

 

I think its a posi rear end, he claims it to be one, and my old 86 WS6 had a stock posi.

 

Honestly I would not waste a dime on that 305. Do yourself a favor and try to find a low mileage Vortec 350 and change the intake and put a carb on it. That should be able to be done for cheap.

 

I'd recommend just doing a 350 swap as well, even if its just one of the $2000 GM smogger crates.
But if you really want to wake the 305 up port the base and siamese the runners, it'll free up some RPMs. I know LT1 cams work pretty well in the TBIs, I'd imagine it would wake the 305 TPI up a little as well, they're pretty affordable anyway.

 

I think I am just going to try and get the 305 running in the mean time, I can well imagine it will run like complete crap, and probably even puff blue, I am not going to spend a dime in performance parts though, and anything I do buy will be going on the 350, I think I am going to check my local auto wreckers for a crashed 97 - 99 Silverado they come in quite often and stripped quite fast haha.

 

I found a 97 truck 350 to use for my swap. In my area the salvage yards are asking $700-950 for one. I found mine on craigslist for $350. It runs good but I am going to rebuild it before dropping it in. The only issue I found that is worth noting but easy to resolve is the starter bolt pattern is only drilled for the offset holes. As I am going to use a T56 tranny (found on craigslist from a lower mileage 97 Camaro) I will be drilling and tapping for the inline hole pattern to use the original style or similar starter. If I was running an automatic I would have just swapped the flex plate to the larger 168 tooth version. I feel that for me this is better than hoping to find a flywheel and much more cost and replacement friendly.

 

Here is a 300hp 305 build...

CarCraft 300hp 305 build

So yes, you can spruce up the 305. It's just everyone's opinion that a 350 is "better".

 

After 11 years it may take awhile to get that 305 going. If you can, I'd probably drive it as is until you really figure out what you want to do and have the resources to do it. Whatever you decide, Good luck with it and post some pictures when you get it home.

 

By every measurable metric a 350 is better. You can spruce up a 265 too...

Be wary of magazine hp results. They're normally on engine dynos where the engine has massive headers, giant intake, perfectly tuned carb, and it doesnt even have to turn its own accessories. Real world numbers are a lot closer to 75% of what any magazine article is claiming, depending on other factors. Their testing methodology makes a lot of sense for comparing to other magazine article builds without have aspects of the car its going into figuring into the final power levels. But it's not the real world number you're going to get. The gains are there, but a 300fwhp 305 is a pretty stout engine, it will cost money or drivability to get there.

Their basic engine is milled vortec heads and an xe262 cam and a giant single plane intake. Not a bad combo, but you'll need a much more tame intake to fit it under the factory hood. SUrprisingly, they actually do have this engine turning the water pump, but no alternator or power steering pump.

 

You have an LG4/T5 with either a 3.23 or 3.73 rear end. I wouldn't be surprised if simply installing a new battery, fresh oil and gas gets the car running. Put in in gear and rock the car. If the balancer moves, the engine is not frozen.

If you get it, post a pic of the SPID sticker in the console and I can tell exactly what it has.

As far as "sprucing it up" for cheap, *if it were me*, I'd find a TPI or L69 exhaust, complete with manifolds, (an N10 would be sweet but hard to find), HO air cleaner, (see them for sale on this site all of the time), bump up the timing a few degrees and call it a day.