I am using an early NOS 400Jr Isky cam in a 8BA block with a merc crank and your part number 56056312 adaptor on the cam. Also in use is your 8BA 49-53 timing gear, crank gear and timing cover 56056310. Upon assembly, I noticed a gap between the distributor gear on the cam and the machined surface on the cover designed to prevent cam walk of about 1/8 of an inch by eye. This would be way out of spec for cam walk. After thinking, should I be using the 48 timing gear and crank gear to direct the thrust to the back of the block considering I am using the early cam in the later block? I had to have the timing gear machined slightly to accept the adaptor. I just assumed the adaptor would work with the later gears. Again and after thinking it is probably less common to run an early cam in a later block so there isn’t a ton of info on this. Thank you very much!
The part numbers you are describing are parts that are sold exclusively through Speedway with our name on it. We don’t manufacture these parts or know any of the specifications for them. We suggest you contact Speedway for more information or speak with an engine builder. Thank you.