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View Full Version : L31 comp cam 08-501-8 swap



illusionman101
04-22-2012, 07:38 AM
Hello everyone, this is my first post and I have a few questions about a cam swap in my tahoe.
I am looking towards the comp cam 08-501-8 while running the stock rocker arms. The main questions I have are what springs and retainers should I run? I was looking at the comp cams part number 986-16. But will these require machining on the heads? I want to do the swap with the engine still in my truck and I really do not want to pull the heads for machining. any suggestions would be great. Thanks!

Doober
04-22-2012, 04:46 PM
The only way you will get away with not pulling the heads is running beehive springs or running a cam under .480" of lift. I have the same cam but with 110º lobe separation, and it makes a ton of torque down low in my 383. It's a great daily driver cam, the only issue you may have on tuning is with the tighter LSA, which may not be an issue since Vortecs are MAF. My heads were cut down for stock style SBC springs (Vortec springs don't have a damper) + more lift, and cut/tapped for screw-in studs. Screw in studs only makes sense to me when you go with a performance cam, especially a roller... otherwise you may risk pulling a pressed-in stud. I'm also running stock rocker arms, but may upgrade to some aftermarket arms since the stockers are only stamped.
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=186&sb=2

96ImpSS
04-24-2012, 05:47 PM
That 501 cam will work great in an L31.

CC 26918/26915 Beehives. CC 787 retainers. No machining required.
No worry about the pressed in studs. Stock rockers work fine with that cam.

Or you can try these springs for about half the price:
http://www.alexsparts.com/products/BEEHIVE-VALVE-SPRINGS%2C-SBC%2C-VORTEC-%26-LS-SERIES%2C-STOCK-TO-MILD.html
I've not used them; many have and I've not heard of disappointments. You can find the retainers there too.

TheBigMortboski
04-24-2012, 07:17 PM
I know when I was building my first car, we just used Z/28 valve springs if we had a mild street cam. That was right when the Vortech engines were coming out, though, so I don't know if they'd work. And that was with press in studs, also.

illusionman101
05-03-2012, 05:46 PM
Thanks guys for the help, I'm going with the springs from Alex's parts and 787 retainers and a tune from Justin at Blackbear. Also going to replace the waterpump as long as I am down there and since it is original. Do you guys recommend I replace the timing chain as well? I've personally never heard of one breaking on a SBC but I also haven't been around the block yet.

TheBigMortboski
05-03-2012, 06:01 PM
I haven't heard of one breaking, but they stretch over time slightly. Most dudes replace them because they want to go to a double roller.

Doober
05-03-2012, 06:05 PM
Any time I do a swap like that I check the chain... if it has slop it gets changed. Typically any time I've taken an engine that far apart it was for a rebuild anyway. A true roller for flat tappets isn't very expensive, a decent double roller chain for factory-equipped roller cams costs a bit more but I figure it's worth it (how often do you really pull the timing cover off?).