broknindarkagain

I'm not sure if this is posted in the right forum.....if its better somewhere else can a mod move it please?


First off, here are the specs of my truck

1993 Chevrolet Cheyenne Stepside Shortbed
5 speed 4x4
305 Throttle Body Injection


I'm looking into doing a motor swap on my truck. There are some repairs needed on my motor, and it will be cheaper to replace the motor rather then repair.

I found a killer deal on a 305 carb motor that is coming out of an 84 Blazer, so it looks like this is what I'm going to be putting into my truck.

I know that the motor will bolt up easily, but getting it running is a different story.

My understanding is that the fuel pump and distributor are both computer controlled on the 93. So I guess I would have to replace the fuel pump and rewire everything, including a power wire to the distributor.

Another option that I've been thinking about is taking the intake and TBI unit from the 93 motor and putting them on the 84 motor, that way I could keep the emission systems and would avoid rewiring things as well as fuel pressure problems. I do know about the angle of the middle 4 bolts being different on the two intakes, but I've been told that you can dremel the hole a little bit to get the intake to bolt up properly. My main concern is a sensor that sits on the side of the block on the 93 motor (by the #1 cylinder....maybe a knock sensor????) that I didn't see on the 84 motor when i looked at it. Another issue with the intake swaps is the 84 and 93 distributors have different gears on them, so if I put the 93 dist on the 84 cam, the gears on one or the other....or both will get chewed up and it will keep jumping timing. Is there any work around for this?

I'm pretty dead set on swaping with this 84 305....It has a performance cam in it, its been bored .30 over, and the heads are ported and polished....so Its a mildly built motor....Not only that but it has less then 50k miles on it since its been built. It has an edelbrok intake on it with a Holly 4bbl carb as well.....and I would like to keep it that way if possible.

Has anyone ever done anything like this? Any info or advise that anyone can shed on this would be great.

Thanks for any help

broknindarkagain

I'm in the Atlanta area of Georgia, so I am required to do emission testing. Basic law is you can do whatever you want as long as you have a cat converter on it.

There is one thing I'm looking into however. There is whats called the "hot rod" exemption. Basically, if you convert the motor to something that wasn't available for that truck during that model year it will be considered a hot rod and be exempt from any emission testing. I don't know if this would apply or not because I'm switching to another 305, but its a different year motor with a different type of injection.

However, if a carb motor is tuned right you should be able to pass emissions no problem.

Blindsight

If you want to keep the modified motor the way it is, then I would suggest pursuing your rewiring option. Rewiring those things will be a pain, as wiring tends to be, but it's better than losing the Carb on the built 305 and also risking a mistake with the dremel and possibly ruining the block.

broknindarkagain

I'm leaning towards leaving the carb. I talked to a GM guy the other day and he said that it isn't that hard.....He said that the wiring isn't much (battery to starter and so on) and to run a mechanical fuel pump.

On the note of ruining the block, its the intake that you risk with the dremel. The middle 4 bolts are angled different, so you have to dremel the holes on the intake so the bolt will hit the hole in the head.