85transamtpi

Now that I know I can do my cam swap with the engine in the car, I need to choose a cam. The two I am looking at are summit's tpi cam (204/214 duration .420/.442 lift), and Crane's compucam (264/274 duration .423/.446 lift). Both cams say they are designed to work with my engine so why the big differences in duration? Which will work better with my 85 LB9 (700r4 with stock converter)?
thanks

Ray87Z

They are both nearly identical cams, the duration rating on the Summit cam is given at .050. The specs you have from the CompuCam are not. At .050 the duration on the CompuCam 2030 is also 204/214 I believe. Nearly identical cams specs wise like I said.

I am running a GM cam grind that specs out to the same as the summit cam (204/214 @.050, .420/.442 for lift) in my 86 IROC's 305 TPI. It idles and runs well w/ both the stock chip and my ADS chip.

{EDIT}!! Sh*t, I just noticed you have a 85. It has a 202/207 @.050 cam in it already. You would be wasting your time in my opinion to only step up to 204/214. If you had the peanut cam that is in 86 up 305 TPI auto cars (like 178/190 duration or something) then the 204/214 cam would be a good upgrade. Give Crane a call and see if they don't have a compucam that is slightly bigger if you're still intent on changing it. I want to say they have a 2031 that is a hydraulic lifter cam and has around the 210/220 mark for duration. I've forgetten the specs on the 2040 but you might look into that as well. Having said that though there are other areas where you could better spend your time/money if you're near stock. (headers, cat-back, intake porting, etc). The stock 85 cam is not that bad.

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited September 22, 2000).]

FastBroker

The Summit (cheaper) cams and the GM cams are made by the same mfr, hence the same numbers. Also, I believe that it COULD be Crane that makes them, too. Crane will "adjust" the spec's slightly to think you are getting a different/better cam but really they just put there name on it and raise the price. Go with the Summit cam/lifters. I have used this cam on several occasions and it really is a great cam w/Performer manifold and just a moderately tweaked exhaust...

Look at the other generic cams in the GM catalog. They match the Summit cams exactly. (ie 194/204 and 214/224)

[This message has been edited by FastBroker (edited September 22, 2000).]