Hey, guys - I'm building a 427 small block stroker for my 66 Corvette and I've got a bit of a head scratcher that I could use some help with. I'm using a Dart SHP block and a 0,900" base circle Comp Cam (custom grind). I purchased Chevy Performance roller lifters - the kind that use the spider tray and dog bones. Now I'm worried that the small base circle is going to be a problem with this lifter style.
With the cam and lifters installed in the engine, the small base circle is causing the lifters to "ride lower" than I think is normal. It's clear that the lifters don't drop completely into the lifter bore - they stay proud of the bore at all times. As closest and I can measure, I still have about 0.060" of engagement between the "shoulder" of the lifters and the dog bones and the lowest point of lifter travel, so they can't rotate in the bore. But the dog bones aren't BOLTED in place - just held down by the spider tray. Is there a chance that the dog bones could lift during engine operation and allow the lifter to rotate? I just don't know if my 0.060" of engagement is enough! I can buy longer pushrods to account for the small base circle, but want to make sure I'm not setting myself up for a problem.

Advice? Switching to link bar lifters (which have to already be 0.300" longer than normal due to the Dart block) will be an expense I'm trying to avoid.

 

Buy Dog bone lifters,cheaper than having the lifter turn out of guide plate and munch up cam
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Get link-bar lifters. Or use a standard base circle cam, but you'll have to check and adjust the clearance of the cam lobes to the connecting rods on those that don't have 0.050" clearance, or you could use stroker rods that have more clearance.