Hi, Im Ted, Im new to this site I just bought a 86 trans am 350 5sp

First question is It has a 350 put into it, but its a fuel injected block that was switched over to carb, the person I bought it off really knows nothing about cars and didnt do the swap himself. Im just wondering why someone would switch it to carb, and if it would be better/expencive to switch it back. I dont know what the engine was originally, is there a way to tell looking at it?

Also, the car has a aftermarket locker, It is geared really tall and I was looking at putting some 373's in it before the snow is gone and was wondering if the locker will work with different gearing.

With this car im hoping to wind up with around a 300whp car, mostly going to worry about handling and braking cause theres a race track in town ID like to take it to. (i played with silly jap cars for years)

Anyway, I hope I didnt ask anything too silly. thanks for any help!

 

To switch back to the FI system may be costly if you don't have any of the original parts. It was a TPI car - so you'll need all the TPI parts (intake, injectors, all that), plus all the sensors (O2, MAF, CTS, TPS, IAC, etc.) plus all the wiring if it's been hacked out, plus the ECM and a prom for a 350 TPI. Then there's hooking it all back up, could be weeks or longer depending on how bad things got hacked. In the end would be cheaper probably to get a TPI car with a blown motor/tranny and swap everything back into your car to go back to FI.

There's questions that beg to be answered here, since alot of carb swaps are done wrongly ...

1) Is the intank fuel pump from the old FI system still in the tank?
2) Is it being used, or is there another fuel pump been added?
3) Is there a return-style fuel pressure regulator?

Some other things to consider ...

1) This "locker" - is it a true locker, or is a posi-traction unit? There is a difference - locker keep both axles locked always, posi-traction is a 'limited slip" system that allows one wheel to 'slip' without getting power if needed.

Lockers are for strip cars ONLY - not good on the street. LSD or limited slip are for street, allows the inner wheel to travel at a slower speed than the out wheel without breaking axles/gears on turns -what you WANT for a street driven car. So, if it has a true "locker" unit in it, you need to get it out if going to street drive this car.

2) Tranny ... the 5sp tranny will not hold up to the power of a 350 motor, thus why GM never offered a factory 350/5sp option. So - you're going to have to baby the car - no clutch dumps, no burnouts, no drag racing with that tranny. Otherwise you'll be walking to the bus stop.

3) Gearing can be swapped. Not something I would do in the driveway, but I guess it's possible. You have to determine what series carrier you currently have, and get gears for that carrier. There are strict tolerances in setting lash when installing new gears, etc., and it's something that I'd leave to a pro, but some folks do their own.

Going back to the "locker vs. LSD" discussion, if you have a true locker installed rather than a LSD, then my recommendation would be to get an entirely new rear end (by new I mean new to you, not brand new), with the LSD and the gearing you want. Swapping in a complete rear is an easy 3 hour job, and way cheaper than paying a shop to rebuild your differential. Any other 3rd gen rear will swap right in (but only F-body rears), as well as any 4th gen rear. 4th gen rears are nice because they are cheap ($300), can be easily gotten with better gearing (many 3.42's out there), most have LSD system (a Zexel-Torsen type), and most all have rear disc brakes (nice bonus). The downside is the entire rear is about 3inches longer overall, so your stock wheels stick out about 1.5inches farther each side. Oh - and you have to have 16" wheels to fit over the 1998+ rear discs.

Hope that helps some! And welcome to TGO!

 

Welcome to TGO, Ted.

An '86 could have been carb from the factory. If so, converting to EFI would be even more difficult.

Whether or not you could put different gears on your locker depends upon what "series" gears it was made for. Most likely you could put 3.73's on it, though.

Oh, I like my Detroit locker...