This engine comes with a hydraulic roller camshaft with 215/223 degrees of duration at 0.050-inch tappet lift with 0.473/0.473-inch valve lift. You didn’t mention which hydraulic roller crate engine you were interested in, but the least expensive small-block Chevy crate engine in the Chevrolet Performance catalog with a hydraulic roller camshaft is the SP350/357 long block (PN 19367080).

All eight dog bones were held in place by a large steel spring fixture retained in the lifter valley with three bolts using eight legs (also known as a spider) to hold the dog bones in place.

One dog bone was used to retain a pair of hydraulic roller lifters to prevent the lifters from rotating which would destroy the camshaft. The block was modified to accept a hydraulic roller cam arrangement using what are called dog bones to retain the hydraulic roller lifters. Among the changes was a one-piece rear main seal and, in passenger cars, these engines received hydraulic roller camshafts. In 1986, GM upgraded the small-block in several ways. It is listed under PN NAL-12681429 at Summit Racing. The least-expensive and still popular small-block Chevy crate engine is a built-in-Mexico hold-over from the traditional two-piece rear main seal engine configuration that started in 1955 and ran until 1985. A little history on the small-block Chevy is in order here. The hydraulic roller cam conversion kit that you mentioned is intended to upgrade Chevy’s one-piece rear main seal small-block engines. We’ll go into much more detail so you know why and which engines would benefit from a conversion like this. Unfortunately, the short answer is that this approach will not work. Rather than buy the more expensive roller cam Chevy crate engine, why can’t I just use that Chevrolet Performance hydraulic roller lifter kit - PN 12371042? It seems that adding the roller cam would be the least-expensive way to go. I’d like to upgrade to a hydraulic roller cam at the same time. I am considering buying the basic Chevrolet 350 c.i.d. The only issue is that this can only be used in a factory one-piece rear main seal bock that is machined to accept both the dog bones and the spider.

This is a very affordable lifter package priced well under $500. This is the factory hydraulic roller lifter package referenced in the story.

Chevy 350 roller cam kit