'66 390HP CAM REPLACEMENT

[Rob A.]

Crane is currently out of stock of their "blueprint" series cam(#969391) that duplicates the original GM#3883986. The closest, in stock (#113902) cam they have has the following specs: LIFT @ VALVE 484 INT 515 EXH

ADV DURATION 260 INT 272 EXH

LIFT @ .050 204 INT 216 EXH
Advertised to idle smooth, with min rpm 1500, max rpm 4500

I really don't want to wait several weeks for their "blueprint" cam to be available, if this slightly more aggressive cam sounds like a good choice. Any thoughts?

[Clem Z.]

Re: '66 390HP CAM REPLACEMENT

GM performance parts list the part #12364055,cam and lifters made by crane

[Joe L.]

Re: '66 390HP CAM REPLACEMENT

Rob------

I think that cam would be fine. However, if you want to use an exact reproduction cam, you may be able to obtain the GM kit. This is a Crane-manufactured reproduction of the GM #3883986 + lifters. While Crane may be out of stock, GMSPO may not be. The GM part number for the kit is GM #12364055.

[Rob A.]

Re: '66 390HP CAM REPLACEMENT

Thanks, I'll call them tomorrow...

[Rob A.]

Re: '66 390HP CAM REPLACEMENT

Thanks again...

[Rob A.]

Re: '66 390HP CAM REPLACEMENT

Joe,

I don't want to overdue my cam replacement discussion, but, I talked to the owner of a local corvette repair facility today(Costa Mesa, CA) who is very familiar with cams, their specs and seems to have a complete understanding of how the cam will effect my '66 390HP engine, including idling, compression, pinging, etc. He says that camshafts are his "specialty" in these year cars. After a lengthy discussion he recommended a crane #133942. Its' specs are: min rpm 2000/max 5000 LIFT@VALVE 515INT/510EXH LIFT@.050 216INT/228EXH ADV DUR 272INT/284EXH 112 LOBE CNTR. I'm beginning to understand which of these specs are important in my selection and would like your thoughts(again).

[Joe L.]

Re: '66 390HP CAM REPLACEMENT

Rob-----

I think that the Crane cam you decribed would be a fine cam for the application. It would provide very good driveability and more power than the original camshaft. You won't be "over-camming" the engine with this camshaft and you'll be taking advantage of modern cam technology. However, I thought that what you were after was an exact original spec cam. Obviously, this camshaft won't be that.

[Rob A.]

Re: '66 390HP CAM REPLACEMENT

Thanks again Joe, I installed a crane "blueprint" cam in my '67 400HP car, and it runs fine. I thought I'd try something a bit different in this car, partly since crane is replacing the one I removed under warranty, so I have to get it from them, and they will be out of stock on the "blueprint" cams for another two weeks. Thanks for your input...