I have a 1996 Z28 and im looking into the LT1 to LT4 conversion kit from Jegs. I was just wondering how much power gain will i be looking at and would it be less of a hassle just to take the engine completly out of the car.

 

The LT4s made about 335-350HP depending on the car...figure the hot cam will be good for a lil more power...your lookin at about 375HP at the fly i would guestimate...also, if your doing the top end then you might consider dropping the motor down anyway since these are a bitch to work on...GMpartsdirect.com also sells the LT1-LT4 conversion and is usually very cheap, worth the price comparison...

 

LT4 Heads/Intake/Hotcam should be good for around 360rwhp in a tuned 6 speed car.

You might consider some porting on the heads/intake and possibly a 58mm TB if you're wanting a bit more power.

It's up to you on how you do it. It would probably take slightly longer to pull the motor but it will make working on it easier.

 

I did this conversion on my 94 vette and I highly recommend it,about 360 horse at the rear wheels.

 

For the same money spent on porting the stock heads you can have more rwhp than the LT4 delivers at the flywheel.

The LT4 kit was a reasonable choice a decade ago, today there are better options, much better.

http://web.camaross.com/forums/showthread.php?t=567396

 

The kit keeps it all GM in a way though. It's kind of neat in that respect.

 

360RWHP is definatly attainable if you have all the supporting mods and boltons and a good tune...and I agree there are definatly a lot of other options out there...being GM all the way is not a big deal unless your talking about an alternator or an Opti, then I wouldnt get anything else but GM...AFR, Trickflow, all make great heads...

I would check out Lloyd Elliots page if you havent seen it before, great packages and reasonable prices...

 

i have a 97 z28 and im also thinking about the LT4 conversion kit, i was also going to get the 58mm tb, and a set of hooker headers. what do you think i could get out of that combo? i dont mind spending some money on the car.

 

The LT4 package is a rather poor idea. If you really still want it then nobody can help you much, you already ignored all the good input.

Couple months ago a guy got NASTY about my saying these things said the LT4 package was awesome, then he went to the track and found out the car ran horribly, he just had no frame of reference till he raced it and got the timeslip that told the real story. He posted abnout it but then deleted the thread when I crosslinked his ranting about how great it was to the thread about the BAD results.

 

Did you even read this thread?

 

To say that is pretty ignorant. It's a combo that has proven to make power. Yes its old tech and new tech can/usually be better. But to say that it is a poor idea is rediculous.

I'm just running the HOT cam and ran a 12.4. If I had long tubes and a y-pipe, probably 12.2. Add the heads/intake, bottom 12's and probably dip into the 11's. That was almost 10 years ago, full weight and emissions legal also.

Saying one guys results make the whole combo a bad idea

 

ok did anyone mention another combo? i never said i was going to get it, i said i was thinking about it. and from what alot of people are saying, its not that bad of a choice. what would you recomend i do. Enlighten me.

 

lol i went back and read it over again and yes i just asked the same question again. i also for got to mention that i wanted to get a 383 stroker kit along with the LT4 conversion. i was wondering, if anyone else has done that combo and if the results were worth the money?

 

GM's LT4 kit would not support the airflow that a good 383 would need.

 

Don't know what else is in "the kit", but the Heads and Intake certainly would!!!
All most everyone is running ported LT1 heads and intakes on their 383's.
I'm not saying it would be cheaper but to say LT4 stuff won't work is just NOT true!