I have a 93 z28 with 100 shot of nitrous, K&N cold air, flow master and ecm work.I was thinking bout the lt4 conversion kit with the heads and cam (dont know specs)pacesetter headers, torque converter(dont know what size)and a gear possibly a 4.11.They say that kit makes 425 hp any truth cuz thats about were Id like to be.Any tips or advice would be appreciated.

 

Yes theLT4 kit can make 425FLYWHEEL hp BUT these days that is a pretty sad number. Yes you read that right, 425hp from heads and cam is nowhere near enough, it is LOW.

http://ls1tech.com/forums/lt1-lt4-mo...s-429rwhp.html
Granted that is an M6 not an A4 but seeing as it made more rear wheel than the LT4 kit does flywheel it makes my point. With an A4 it will be lower, say 400ish at the wheels.

On the converter I have a 3400 stall Edge Racing Converter, very happy with it on the street and strip.

 

Well im no expert, but from what ive read you will be better contacting lloyd elliot or AI and having them port your heads, intake and custom cam. (around same price but more power). also everyones going to ask if its a m6 or a4. if its an auto go with 3.73's if its m6 4.11's.

 

LT4 conv. is a rip. Make much more power going about it some other way.

 

For less money and more power you could have your heads worked, and put a real cam in. For close to the same money could buy some great aftermarket heads....LT-4 kit is a rip!

 

I'd go with Lloyd Elliot heads and cam package and port your intake. you will spend less money on that than the LT4 conversioin kit. On a stall converter I'd suggest a circle D out of Houston, Tx. Very good converters and they have very consistant 60' times.

 

I have done the LT4 conversion. Most power I have gotten to the wheels is 340Hp and this is with an Auto. Heads are mildly ported as well as the Intake. 30 LBS SVO injectors, 52 MM TB, BBk shorty headers and Borla exhaust with no plate. 3000 Koan stall and 3:73 in the rear. Only reason I did the conversion is i got the parts cheap. If I had to pay full price, I would of went a different route. I know the Cam itself is killing the numbers. Reason I didnt go with a different Cam was for Emissions.

 

The LT4 kit doesn't even make 425 flywheel HP. The people who sell the kit advertise that based on a magazine article done by MORE Performance, more than 10 years ago. The engine was run on an engine dyno, with no accessories (SAE "net" requires all accessories to be installed, as in the basic car model), using a $3,500 aftermarket ECU and I suspect numerous other mods that they conveniently failed to mention.