i want to get the lt4 hot cam, i was just wondering if this will be too much for all of the stock valvetrain and other stuff? i have heard that all i will need to get is new springs, is this true?

thanks,
david

 

I would do it if it was a 91 car just because it is getting old. At the same time, I would check the valve guides for wear and replace the seals if everythig was good. In any case, the head is almost out so you might as well take it out for a good test. That is assuming that the leakdown test shows that the rings are still good.

 

Yes, the LT4 cam has lift in the .5xx region--way to much for the stock valve train. You will almost certainly have to have the heads machined for taller valve springs.

But an LT1 cam might work without any mods to the heads.

 

he prolly wants a real cam tho......
the lt4 hot cam does not have lift in the .5 range unless you are running 1.6 rockers...

 

.492 with 1.5:1 rockers .525 with 1.6:1 rockers, but if you get the LT4 Hot Cam kit it comes with 1.6 roller rockers and LT4 springs, witch for the price would be the way to go.

Martin

 

at minimum new springs and matching retainers. the lt4 springs require 101# closed pressure at 1.780 height. and have a rate of #332 in/lbs. the stock springs when new have 80# seat pressure. so with the old springs on, the valves will bounce off the seat and beat them up over time. can you run the came w/o new springs? sure many have. in the long run you'll wear out the valve seats.