I have a (89 Firebird Formula) stock 305 auto, they come manual as well. I plan to engine swap into a LS1, and a manual transmission. Could I take a Stock 89 Firebird Formula Manual transmission and then put a LS1 on it? If so why, or why not I want to learn

 

You could, but you'll be on very borrowed time and run the possibility of breaking it, i'm not sure what T5's are selling for now, but even if you could get $400 out of it in good shape, you'd only be 400-500$ from being able to get a T56.

 

So youre saying I should look into a t5 or t6 transmission? What are the major differences? Is the more expensive t6 worth it?

 

The T56, its whats used behind the LS1 from the factory, its a 6 speed manual, it was designed to actually handle the power, yes the price difference is very much worth it.

 

Id steer away from the T-5. They blow under most stock 305s.. some people have luck tho. Never seen one mated behind the ls1 tho either. I'd save up for the t56. Make sure its the tremec version and has ls1 bellhousing. The lt1 t56 will work but will have to change input shaft and bellhousing which can get costly.

 

t-6 it is! ha now would you recommend getting one before the other or at the same time? I know ideally youd do them both simultaneously but is it really that big of a deal? For example I was thinking Id get the transmission first, then the motor, later on down the road. Will that have consequences?

 

It doesnt really matter. But i would probably get trans first just because they are hard to come by and always seam to hold up a project. Plus if decide not to go with ls1 you can still change bell housing and run it behind a sbc or something else which will make it even more fun.