Im peicing my engine back together and came across a few questions...

First, would the pushrods used on a regular set of heads be different length than those used with vortec heads?

Second, i have two sets of lifters in my garage and its been a while sinc eive seen everything... Are lifters for chevy basically the same diameter? B/c i have one set that doesnt slide into the lifter holes...

anyway, any input would be nice...

In general, it's the type of lifter that determines the length of pushrod. Flat tappet lifters use longer pushrods than factory roller lifters. '86 vs. Vortec heads doesn't change that (does change the type of rocker arms, though).

SBC's and BBC's all use the same lifters. If you have some that don't slide into the lifter bores, they aren't stock-diameter Chevy lifters.

You could always take some measurements for comparison.