Stockish 340 upgrades, cam needed

I always first recommend using the springs that the cam grinder but, here is PAC single spring that comes close to a Howard's 98438. 416 pound rate instead of 420, and has an actual I.D. of 1.06 like the Edelbrock 5767 so it could be used with the 9736 retainers. I would rather see a full O.D. retainer to match the springs, though. But, for someone in a pinch, these still fit the usual 1.49 inch diameter Edelbrock spring pockets. And I have also found that you always need to double check Summits spring information to the actual spring manufacturers catalog. They are seldom 100% correct on I.D. or O.D., as is the case here. If set at an installed height of 1.77 (.030 shims), the seat and open rates are the same as the Howard's double springs.
PAC Racing Hot Rod Series Valve Springs PAC-1927-16