LT4 Conversion Kit

Few questions, if I keep my 3.23 gears and with an extra 150 horses or so, what 1/4 mile times could I expect around? Also, could I keep my 4L60E transmission with 425 horses? Any other feedback would be greatly appreciated. My car is all stock right now, btw. '95 Z28

 

waste of money if your going for performace. just port your own heads and add a cam and be done with it. and buy the way thats not 425 Rwhp thats fly wheel. with 20% drivetrain loss that only nets you 340 rwhp.

 

Not only is that 425 not at the rear wheels, it's assuming headers, catback, a pcm tune, and probably a cold air intake is already in place. Do you already have the major bolt on items?

 

I don't see the assumption about those bolt on mods already being in place?

 

I sold my 1993 V6 Camaro for my conversion kit which had the LT4 heads already ported by Lyodd Elliot. I was astounded by the performance increase. BUT.... that was with ported heads and a Hotcam.

You would be much better off using that money to buy a 4 bolt main LT4 block rather than the LT4 top end which is so unbelievably close to the LT1 that it is not worth it.

If you plan on porting and polishing heads than the LT4 is great, but buy it used...

 

The cam and heads mean more air/fuel in and more exhaust out, hence more power. Without the means in place to accommodate that, you're not going to get what the kit or any other aftermarket cam & heads kit is capable of.

As for tuning the pcm for the cam, it only makes sense. Why change the valvetrain around and not make the most of what you just installed? You'd be leaving untapped power on the table.

Work your way towards the engine, not the other way around. Start out with the cold air, exhaust and/or cut out, then headers. Once these things are in place, you'll be able to make the most out of whatever cam & heads combo you choose. PLUS - you'll see and feel gains every step of the way.

 

You're right. Should start with the small mods first. Thanks.

 

If you're set to go ahead, check out this GM PP supplier. good prices.

http://samtaylor.com/html/parts.html

Steve

 

Everyone's going to tell you its a waste of money....because it is if you're going for performance.

 

If your going for high horsepower, then you have more things to worry about then engine right now. First, you need a strong transmission, and a strong rearend. LT4 kit is great if you plan on porting it.