kcb37

NCHEVYHEVN
I have not seen an underdrive pulley set without a crank pulley, All I said is for a stock or close to stock setup it ins't really worth the money you have to spend on them.

NCHEVYHEVN

Actually they are one of the better BOLT-on mods you can do on the 4.3 Granted it's not as good as a cam but it definatly ranks up there with getting the larger y-pipe and the electric fan as far as bolt-ons. Definatly alot better than waisting your money on a $250 intake that does almost nothing or $300 MAF sensor that can make it run worse and throw codes.

kcb37

When you put on an intake you have to macth it to your engine. If you get a cheap one it won't do a lot, similar to cheap headers having greater probems leaking. If you get bigger ports, and bigger exhaust it will help, a cam to boot will do a lot. This is why a lot of people will take the intake they have and have it ported, it will flow more air. Bigger valves on a non vortex will also add a lot to this to get more of that air in the cylinders. Vortex's should be fine as they already have bigger valves and the computer will adjust the fuel air. And a MAF sensor will help with a good intake to let the engine breathe better.

NCHEVYHEVN

I have to disagree.

A) It's called Vortec not Vortex. Also Vortec is just simply the manufacturers name.
B) I think your getting confused when I say intake I mean as the intake tube rather than the intake manifold. And you can get just as little performance from an intake from ebay as you can from a more expensive K&N intake. When I say little I mean like if your luck 2-3hp. All it really does is make a cool sound when you go to WOT. I cut the bottom of the my factory airbox off and it does the same thing.
C) As far as aftermarket MAF the negative effects you can get from far outweigh their little performance gains also. The can cause the motors to lean way way out. And for 300 bucks you can save and put towards a cam which isn't much more.

Like I said top 3 bolt on easy mods you can do is the y-pipe, electric fan(s), and the underdrive pulleys.

kcb37

So I hit the wrong key. Vortec is a name similar to Shelby Mustangs, but Shelby redsigned those engine to create more power. The vortec has heads based off of it I remeber correctly the LT-1 and also have bigger valves than the older model, thus more power. So yes it is a name but not simple just a name. If you research this you will find that info.
I will agree the 3 together should give a noticable power gain, but by themselves will not do a lot.

NCHEVYHEVN

Yes, 1996 newer heads were put on when the switched from TBI to MFI. The heads and actually the whole motor is based off the 350. It's just missing two cylinders which I beleive if you look at them would be #2 and #6 cylinders. The 1996+ heads flow a ton better than the older ones.

kcb37

Some of the 96 and I think not sure 97's have CSFI

NCHEVYHEVN

Ooops their not MFI. Your right they switched over in 96 CSFI. Good catch.

kcb37

After the CSFI it went to MPFI, Muti-port. I suppose I see why you didn't add the p now kinda one word. Had to see it.