Do I have to run TBI on my 1987 GMC full size Jimmy?

Question

I have this truck that I love but it runs terribly! It has a 305 in it now and I have read that it is suppose to have a 350. Can I drop a 350 motor in it that DOESN'T have TBI, I think it would help it run but any suggestions would be great! Thanks in advance!

Answer 1

Even the 350 is tame in a truck that size. If your going to swap engines, go for a 454 or 500. You have the space. As far as fuel delivery goes, it really depends on what state your in and what the smog laws are like. I'm assuming since you drive a large SUV, you don't really care about fuel economy. There are plenty of after market carburetors and port fuel injection kits for the 305 or 350.

Answer 2

I own a shop, and yes you can. It shouldn't be too much trouble to do it either since they are both small block engines. The way to go would be to put a 350 Vortec engine in it with a carburetor. If you live in a place that you have to run a computer operated engine, then you will have to run a multiport injection, or an aftermarket set up. Edlebrock probably has everything you need to do the job with. Also; you can check out

www.painlessperformance.com

Look at the "Perfect" engine management system, and this will be everything you should ever need to do the job.

If you change to a carburetor, then you can get the linkage for it from a company named "Locar" pretty cheap. You can go to a manual fuel pump from "Holly" that has a return fuel line on it, and it maintains the correct pressure you need. I don't see this as being a big problem, many people do it everyday, and if you are mechanically inclined, you can have it going in no time.

Glad to help out, Good Luck!!!

Answer 3

You can drop pretty much anything you want in it. It all depends on what you want and how much time and money you want to spend. If the question is to drop a motor with a carburator into it, you would have to do a bunch of extra work to the fuel system as in getting rid of the in-tank fuel pump and reconnecting the internal pipes inside the gas tank to make up for the missing fuel pump. Then you would have to run the fuel line to the mechanical pump and up to carb. You woud have linkabe issues, but all of this could be found second hand. If you wanted to run PFI, you would need higher fuel pressure which includes all of above but with a better pump. Plus you would need a completely new PCM and wiring harness to the motor and dash areas. Good luck.