Opinion on 4.3 vortec

[Justin151]

I have a 4.3 in my c1500 and I like it, but I am going to need a new motor soon. I would like to get another 4.3 rebuilt with some internal performance parts then, once its in my truck I can go from there. What would you guys recommend? (without turning this thread into a reason why I should swap it)

[bobfig]

i like my 4.3l, but i have to say they are kinda week. getting a 350 would be a nice power and possible mpg upgrade for around the same price.

[Quyonmob]

Performance builds on a 4.3L aren't cheap as the market for parts is pretty limited. Some 350 stuff interchanges, but real power tickets like heads and cams and pretty limited. Even off teh shelf long tube headers are getting rarer.

[PA.REDNECK]

Yea I agree with them, your going to spend alot of money on upgrades just to get a 4.3 to the stock preformance level of the 5.7, I would just get the 5.7 because you get more power right off the bat and most parts are cheaper, they are both good reliable engines tho

[Justin151]

I think you guys are right. A rebuilt 5.7 only costs about 200 bucks more than a 4.3 and I can't find much performance parts for it. If I went with a 5.7 how hard would it be to install myself? What parts would I need to put it on and what would I have to do to the computer?

[Quyonmob]

Bolt in the 5.7, have the computer tuned for a 5.7L by blackbear, enjoy 25% more power over the 4.3L.

[Justin151]

Awesome, thanks for the help guys, I was 100% sure I was going to get another 4.3 but now it looks like I'm going with the 5.7, I think I'll like it alot more

[bobfig]

yea and the sad part is you will probably get the same mpg's

[Justin151]

My 4.3 is tired and not good on gas at all, I've got almost 347k on it. No knock though, just a tiny leak. It's a tough solid motor, I've been driving it pretty rough lately and haven't seen or heard anything abnormal. Now I just want some real power

[Quyonmob]

Those little 4.3Ls are tough motors. GM was smart to take the tried and true desing of the 5.7 and essentially lop two cylinders off. Made a very durable V6.

[94_c/1500]

Look at the link in my sig for V6 parts.

Really, almost no parts interchange between the V6 and V8 engines. The accessories, lifters, pushrods, springs, rockers, oil pump, pistons, and some of the fuel injection stuff interchange. There's a few other small things, but that's the majority of what interchanges.

What year is this engine? You say it's a C1500, so I'm assuming it's atleast an '88 model. '88-'93 heads are pretty much the same as 350 heads. '94-'95 uses the same heads as the CPI V6 engines. '96+ uses the same style head as '96+ 350s. The '96+ heads are the best flowing. Worked '96+ heads will give you some good flow. But there's alot of different aftermarket heads. Brodix has 18 and 23 degree heads. There's even splayed valve heads, just a matter of finding them and how much you are willing to spend. I'd use either the '96+ heads that have been worked or possibly the 23 degree Brodix heads. It really depends on how much money you have and what year your truck is.

All 4.3L engines with centerbolt valvecovers have a roller cam from the factory. In '96+ engines, the cam is bigger. Aftermarket cams for these engines are practically non existent. In the thread in my sig, I have links to major cam manufactures. If you want an aftermarket cam, I suggest getting a custom grind.

If you have TBI, Edelbrock makes a TBI manifold. They also sell carb intakes, even ones for the '96+ heads. If you want something more serious, marine single planes are out there, check eBay. Or get a used crossram or tunnel ram.

You have a limited selection for aftermarket rotating assemblies. 350 pistons are supposed to be the same. Almost every 4.3L uses an even fire crank, including yours. So that mean 350 rods will not work. You're only option for a crank is really the stock one. If you want more than that, you're gonna have to use a billet crank or a used forged one either of which will be odd fire. If you want to know more on these cranks, let me know.

For blocks, just use a similar year as yours. In the early '90s these engines started using balance shafts. Aftermarket blocks are out there. GM sells aluminum blocks. You can get blocks that can be machined to 4.125 bore. There's even crank support blocks. Good luck finding or even paying for one of these.

Good, impressive power can be made. But it comes with money. Parts aren't cheap as it is, when you build an oddball like tis, expect to pay even more. I like these engines, I really do. I've also spent some considerable time researching it. But, if you are wanting the most bang for your buck, a 350 is probably your best option. If you want to play with a V6, check out my thread. My V6 is stock with some very mild work. My plans just never happened. I got a girlfriend and then we got engaged. Now we're married, life just gets in the way of projects. But, life is more important and more fun than building an engine. If you have any questions, just ask. And more information on the truck wouldn't hurt.

[Chriscon7]

Really, almost no parts interchange between the V6 and V8 engines. The accessories, lifters, pushrods, springs, rockers, oil pump, pistons, and some of the fuel injection stuff interchange. There's a few other small things, but that's the majority of what interchanges.

Seems kinda contradictory for having almost NO parts interchange. As far as performance parts for the 4.3, in this thread that ship has sailed..

But you had some good info on the v6

[94_c/1500]

Heads, intake, crank, rods, distributor, block, cam, timing chain, valve covers, timing chain cover, and the rod bearings aren't interchangeable. So, some of the cheaper parts are interchangerable, and some of the cheaper parts aren't interchangeable. But all of the expensive parts aren't interchangeable, making them even more expensive parts.

Only way you can use V8 rods would be to find an old odd fire V6 crank from the '80s. Kinda rare. Or buy a forged or billet crank, very expensive. As far as I'm aware, no one makes forged ones anymore. You will need V8 rods. And you'll need an oddfire distributor. MSD did sell them, or you can get a factory one from the '80s. The oddfire cranks are stronger. If you need an oddfire crank, you can also get a 3.75 stroke if you use an aftermarket one.

[Chriscon7]

Heads, intake, crank, rods, distributor, block, cam, timing chain, valve covers, timing chain cover, and the rod bearings aren't interchangeable. So, some of the cheaper parts are interchangerable, and some of the cheaper parts aren't interchangeable. But all of the expensive parts aren't interchangeable, making them even more expensive parts.

Only way you can use V8 rods would be to find an old odd fire V6 crank from the '80s. Kinda rare. Or buy a forged or billet crank, very expensive. As far as I'm aware, no one makes forged ones anymore. You will need V8 rods. And you'll need an oddfire distributor. MSD did sell them, or you can get a factory one from the '80s. The oddfire cranks are stronger. If you need an oddfire crank, you can also get a 3.75 stroke if you use an aftermarket one.

Makes me wonder how much power you can get out of a 4.3 naturally aspirated... hmmmm..


EDIT: Leave it to Nelson racing to give me the answer, not N/A but still this thing is a beast
http://www.youtube.com/watch?v=Q5ej6SPKk3w