Intake CL for ZL-1 cam

[John Brown]

I know of a ZL-1 pure stock car that had a 396 375 horse cam swapped in installed straight up, after removing the 180 cam. Cranking compression went up and the car ran faster. Just sayin.....

[TomN]

"These cams have such a late IVC that with a 10.3:1 static comp ratio your dynamic comp ratio is very low."

I realized that but thought I would street drive the car much more than I do and felt that I could run 93 octane gas. Which I can but I get bad performance.

"I know of a ZL-1 pure stock car that had a 396 375 horse cam swapped in"

I have thought of that. Glad you mentioned "straight up" if indeed you mean the same thing as I do by straight up. Car would be much better on the street later with the deeper gears taken out too.

There seems to be several of these ZL-1 cams and it gets hard to compare them all because their specs are all (it seems) given at different values.

Lee's cam: IO 62, IC 105, EO 106, EC 73. ILC 112, ELC 74 (This 74 doesn't sound right)
LSA 109 Wallace Racing Calc gives ELC 106.5
Looks like timing numbers are seat to seat

TRW cam: IO 23, IC 59, EO 72, EC 20. (ILC 108, ELC 116 Per Wallace Racing Calculator)
LSA 112 per/WRC

Clevite cam: IO 23, IC 59, EO 69, EC 24. (ILC 108, ELC 112.5 Per Wallace Racing Calc)
LSA 116.25 per/box it came in LSA 110.3 per/WRC
Per/Box all valve timing at .050"

It looks to me like Lee's cam in ground retarded so I guess/think he did right by advancing it and installing it at 107 degree ICL. I say that because it is such a large cam and that should help to build dynamic compression.

I have seen thoughts where people said you needed a LSA of 114 (like 396/375 cam) to work good with manifolds and exhaust system. If that is so, and the box is correct, would the Clevite cam with a LSA of 116.25 work or is it still wrong because of the long duration it has?

I guess the safe bet is the 396/375 cam even thou it is wrong for a ZL-1, but looking at the numbers above, unless you have a "9180" factory cam you still ain't perfect.