Finally got the LT4 heads and intake on a couple weeks ago. It was a bear to do the heads with the manifolds still in place...but I got it. So far I am quite pleased with the swap even though I am running stock exhaust manifolds and stock cam (time issues). There is a noticeable difference all over the power band, the way the car sounds, the way it pulls etc. It REALLY needs the Hooker LTs put on to get the full effect from the swap though. I noticed quite a bit more torque and a little bit of mid-range..but when it gets up around 5200rpm on the tach...it seems to hang a little longer and take it's time getting to 6K for my shifts.... I think the headers and exhaust will open this up and cure that prob.

 

Yikes....my sig is old..that car is long gone!!

The swap is on a 95z28..my new ride

 

Sweet.
I just bought a set of LT4 heads and LT4 intake to go on top of my 94 LT1 with a 233/239 111lsa Combo cam. I am going to port the **** out of the LT4 heads though.