Valve spring advice

[69 R/T]

I'm going to do a cam swap soon, a .484 lift Comp unit. I already have the recommended 911 valve springs. I want to install these on my stock 906 heads. Should I change the locks and retainers to Comp 10 degree units? Whats the difference between the 741 and 748 part number Comp retainers? Which one should I buy? The spring specs call out either one. Is it even necessary?

 

[IQ52]

Of the two you would use the 748. The 748 is for the 911 valve spring and the 741 is for the 924 dual valve spring.

 

[Frank Mopar]

Look on comp cams web site. They list a min and max for each retainer so a 1.437-1.500 will work up to 1.500 but its actual size is 1.437. So if you need a 1.500, you need order the 1.500-1.550.

Summit list only max size