Hey,

I was wondering if I could get some advice on what to do with my engine but I have to warn you all that it's not a Camaro/Firebird engine. It's a 4.3L out of an '89 GMC Jimmy but I figured I'd ask here because you all seem to know the most about engine related items. I'm totally overhauling this motor and while I've got it apart I'd like to stuff a few more ponies into it. The block's been bored 0.030 and is ready to go but I'm not sure what combo of pistons, cam, exhaust, ignition, etc. to go with. I'm looking to get as much HP as possible with a budget of about $3000. I'm mainly looking for suggestions on what cam will give the most power without sacrificing too much low end torque, what pistons I should go with (keep in mind I need it to run on 87 or 89 octane 'cause it's my daily driver), what ignition parts I should upgrade and any other suggestions you can throw my way.

Here's a list of what I was thinking of doing:

Edelbrock Performer intake
Crane CompuCam (not sure which one yet)
Comp Cams Magnum roller rockers
MSD GM Blaster coil
MSD 8.5mm wires
Headers
CAI
Twin electric fans

Keep in mind it's been bored 0.030 over and I'm using all new parts....crank, cam, lifters, rockers, pistons, valves (old ones are burned beyond help), intake, ignition, exhaust....the whole works.
If possible I'm shooting for a budget of $3000 not including machine work costs. I'm open to any suggestions that don't involve blowers, superchargers, turbos, or nitrous. I want to be able to blow some people away but the only way I'll do it is with all motor! Thank you for any advice you can give me.

~Lucas

 

Need new mounts in the car.

Engine is not gonna fit...

 

The engine isn't coming from or going into a car, it's going right back into the '89 Jimmy. I just came here because a friend said this site was the best he's seen when it comes to tech advice, especially TBI info. I have a basic idea of what I want to do to it, I'm just looking for advice on any additional little tricks anyone knows of that I can do to it as long as I've got it tore apart. I've already done the Ult. TBI, adj. FPR, and injector spacer mods, anything else I can grind down, bore out, etc? I'm already planning on porting and polishing the heads & intake but there's got to be a couple other little things I'm missing that need "adjusting"! Let me know if you think of anything.

~Lucas

 

I have "heard" that the pistons out of a 5.7l I belive will slide in that puppy. Go to cfm-tech.com and get you an over sized tb if its TBI. And no offense, but go to mys10.com and ask this question, I am a regular their as well. Them guys know them 4.3L big time. They can tell you EVERYTHING you can do to that engine.

 

I think the edition of hotrod with the white 89 formula on the cover did a section of how to get 300hp out of a 4.3L check it out

 

I built the 4.3 liter for my brother's truck similar to what you are talking about. This truck is a 1991 GMC Sierra 5 speed. I used the Edelbrock intake, cam, timing chain, and valvesprings. I had the heads worked by a local shop, and we put Manley 2.02" intake and 1.65" exhaust valves in there. We used stainless steel, swirl polished ones. The heads were decked about .015" for just a bit more compression. Edelbrock will send you a chip for free when you purchase the intake and cam. I also used 1.6:1 ratio roller rocker arms. The engine probably produces about 225 HP, which is really good considering the original was about 175, or maybe even less. I used the stock pistons, rods, and crank, and simply bored the engine .030" oversize. The truck runs good, and will 'bark' third gear with a 3.08 geared rear and 265-50-R15 tires. It would not do this stock. Oh, afterward, my brother put on an edelbrock elite series air cleaner and set of valve covers. I could get some pics if you need them, but it would take a couple of days.

Oh yeah, the total cost for the rebuild was about $1850, with me doing all the assembly work. The Edelbrock stuff was about 700 dollars, and the machine work, gaskets, valves, pistons, etc... were approx. $1200. Hope this helps you make some decisions. You can e-mail me if you want to get really specific. There are other things we wanted to do, but our budget was tighter than yours is.