What to do with my '93 4.3L Swap or not?

[AggieENGR]

Hello Everyone, this is my first post here at Automotive Forums. Its great to be here.

I wanted to get some feedback on what I should do with my 1993 4.3L C1500 Cheyenne (114K miles). I've read a little about engine swapping and got really excited about the idea of throwing a big block in, but I know there are lots of hidden costs and potentially annoying issues that can arise. My question is, would it be worth it to upgrade this old 93 or should I look into buying a newer truck with a big block already in it? I just can't stand the lack of power and torque from my V6. I've got to get more displacement. Thank you for your feedback, have a great day


Jim

[Ground Rat]

If you will be able to perform the swap yourself, I'd say go for it. Realize there will be a lot more involved than just an engine swap. The trans and rearend will have to be upgraded too, as well as suspension.

[broughy84]

he's right, if you go to a big block. Why don't you just go to a 350? All you have to do is change the computer and use the injectors off the 350. Not real hard....a big block would definately be harder than a 350....BTW did you know a 4.3L is a 350 with 2 cylinders whacked off of it?

[Rbraczyk]

Does the tranny mate to it?

[AggieENGR]

Ok so if I went with the 350, would I need to upgrade the transmission also? From what I've read, if you want to do it right, there's a lot more involved than just swapping motors and computer chips. If I were to do this I would want it to be just as good as a factory 350. Could I achieve that easily through computer and engine swap? Thanks guys, I really appreciate the feedback.

Jim

[broughy84]

You dont' need to swap trans. The 4.3 & 5.7 have the EXACT SAME bell housing bolts and they mate to the exact same trans, 700r4 or 4l60e. Just pull the motor. don't worry about your trans....i took a trans out of an astro van with the 4.3 in it and put it in my silverado.

[Cadillakin'98]

Thanx for starting this thread aggie, I've been curious as to what all it will take on my '98 when the motor finally gives. I once helped my buddy swap his 4-banger to a 4.2L on his '95 S-10. It took a while to work out all the kinks but seems like going from a 4.3L to a 5.7L would a lot easier. A couple of things noone has spoke about yet that I'm curious of is the wiring harness(es)?!?!? And if the 4L60E mates, does that mean the gears in the rearend woulnd be ok also? I think mine will work because it's different than most factory 4.3's.
I would agree with GroundRat, if you are capable of doing this yourself (vs. mechanic shop(s)), go for it. I've been impressed with my 4.3L but of course I'm itchin' for more like you! And yes, the 4.3 is the exact same block as a 350 but minus the front 2, but still even has the same bore & stroke.
Good luck if you pursue it and it would be greatly appreciated if you kept me up to date!!

[pcollins1]

you could also trick out the 4.3 there are thousands of parts that fit it cams, computers, heads and so on,and then if you race it and win its always fun to say its just a 6 cylinder. ive seen several 4.3's that run better than a 350. but if you really want a bigger engine go for it its not hard if you have the correct wiring harness and computer. both ways are lots of fun. good luck

[cdoogles]

I'm about to swap my 1993 4.3L for a bored out 5.7L also. So, has anyone else tried this yet? It looks to me like the engine will be the simplest part. I'm slightly more concerned about the computers and wiring harnesses. It looks like you have to pull the dash to get the computer out, but Maybe you can get it out through the glove box, but Ihaent tried yet. Luckily I have the entire truck with the V8 sitting in my garage, just slightly totaled so I have all the parts neccessary. Good luck and any info would be appreciated. Thanks guys-

[rpreston]

cdoogles, the ECM is behind the glove box. Easy to get to. I don't think you should have any concerns on the wiring harness. All the engine wiring is essentially the same.

[getusmonster]

I was thinking of doing the same thing with my 95. But i have a 5 speed manual trans. The 5.7l will bolt directly to this tranny and all you have to do i s take off the glove box to swap computers. Wiring is easy just use holes already in firewall that current computer uses. Im hoping this is a very easy swap as i am doing it in Nacogdoches, Texas and there are not alot of mechanics here with any good things to say about them. I let you know what happens.

[getusmonster]

By the way this wouldnt happen to be slim jim would it? Used to go to A&M before was kicked for a couch burning!! Ha HA