I have a 1977 "781" BB head, that I would like to place a set of 911-16 springs on. This is the spring set that is suggested for the Cam I plan on using. I know that no machine work is needed on the head for these springs.
My question is, do I need to change the retainers or keepers? The spec's on the spring is listed below.

Comp Cams part number is 911-16
Seat pressure
122# @ 1.900 Seat.
309# @ 1.400 Open.
Valve lift, up to .530.
Rate - 373 lbs/in.

Thanks,
Fred.

You'll have to measure your stock retainers to see if they match up with the new springs...mainly the diameter of the registers to keep the spring centered on the retainer. Replacing the retainers/keepers is cheap insurance IMO to make sure the springs are located properly.

You'll also need a set of eight exhaust rotator spacers which are .300" thick and have a lip to center the spring. That is unless your engine machinist/builder thinks the rotators are ok to keep using :confused: .

I was where your at before and even though the stock retainers and keepers worked;They didn't seem to be a perfect fit :( .I ended up buying the correct retainers\keepers and doing the work all over again,both times with engine in car.IMO do it right the first ime and save time and know its right.Good luck and Have fun.Tony

Thanks for the information, and I want to do this one time only. So, I agree, buying new retainers is cheap insurance and that's what I'll do.

Thanks,
Fred.

I donno??

Try Competition Products for stock hi-po springs and hardware AND the price is right to me..

pdq67

The retainers for 911 Comp springs are #741 they measure 1.500 1.115 .690. The inside dia of the spring is 1.125. Competition Products has 2 listing for steel retainers:
#3650 measures 1.485 1.115 .715 and #3809 measures 1.500 1.125 .710 They sell these for $42.95 and the rotators are #4779-8 they sell for $29.00. Here is the link for the catalogue.
http://www.competitionproducts.com/2004CompProducts.pdf