Are they 1.32", and is the LT4 valve spring kit a direct swap? Thanks, Chuck ------------------ 87 Formula 350 13.94@96.67 98 Z28 1LE 13.15@107.59 1LE Owners Association

Not sure on the iron heads, but I swapped a set of LT4 valve springs/retainers/keepers on to a set of L98 'vette heads with no fitment problems.

The LT4 springs are larger. You will have to have a machine shop enlarge the spring seats.

------------------
92 Z28 5.7
------------------
Trick Flow 23° heads, Comp Cams XR270HR-10 cam, Accel intake base + ported TPI,
TES headers, Flowmaster catback, MSD ignition, #24 SVO injectors, 1LE aluminum driveshaft.

Click here to see pics of my car !

i beleve they are 1.24" diamiter and the lt4 springs will not fit. That is what the guys at scoggin dickey told me when they looked up the part number. But what is the point in doing all that work on stock heads? i know it is cheaper than buying new heads but it is going to cost you at least $150. There are alot of heads that you can buy pretty cheap that will build alot more power.

------------------
90 IROC l98
last season best corected 13.62 @102
mods
full exhaust, AFPR, pulley, jet stage 1 chip, billet servo, 52mm throttle body, slp runners and some 1.6 RR's and a few other little things.
243 RWHP and 342 RWTQ with hot engine and 90 octain fuel