Recently, while doing a TPI->Carb swap i noticed that when pulling of the intake manifold there was no spider on my Roller motor (350). Nor were the lifters visible at all, only the pushrods. What does this mean? I know for sure the camshaft is roller and it has centerbolt heads. I was told it is a truck motor from 91 (former TBI).

Thanks

 

It has a flat tappet cam, like a lot of the truck engines.

 

IIRC, trucks didn't go roller camshaft until 96, when they went to the Vortec cylinder heads.