I was wondering if the LT4 cam will work with upgraded vortec cylinder heads that can handle .525" lift. Namely these:http://www.sdpc2000.com/cart.asp?act...d=277&pid=9063 from Scoggin-Dickey. Should I use 1.5:1 ratio roller rockers or 1.6:1 ratio roller rockers. These heads and this cam will be going on a GM performance parts L31/ 4 bolt main short block, which can also be found at scoggin-dickey. Thanks a lot.

 

You should call them and ask. They're the ones that modify that head, so they'd know more about it. GM has nothing to do with it.

More than likely you'll need to use the springs that come in the stock LT4, or the Hot Cam kit, which I'm sure they'll do for you if you pay them.

 

Actually I am 90% sure that the upgraded springs they put on their Vortecs are the 1.32" LT4 valve springs. Also, with 1.6 rockers the LT4 hot cam will be exactly .525 lift

 

All the more reason to call them.

 

The add says they are the "Z28" springs, which they sell elsewhere on their site for like $25 for the set. They are 1.25 dia springs I do believe, I have not heard much firsthand experience but several people here seem to not think too highly of them.

Kinda seems to me like you might be pushing it a bit running right at the springs maximum rated lift (of course in other kits of these modded Vortecs from Scoggin they say these same springs are good to .550, so whos to say...).

 

according to this question the cam stated is the lt cam there are three cams that can qualify,Lt1 cam,Lt4 cam and the Lt4 hott cam the only cam that requires the Lt4 hott springs is the hott cam due to the 492 lift w/1.5 rockers but the cam really works better with the 1.6s that will bump the lift to 525 lift.the seats of course need to be cut larger,the guides need to be cut down,the studs need to be pinned or replaced with screw-in studs.....