just one quick question, i was sorta concerned about one article i read on the site that stated tword the end on a hydraulic roller cam that you had to change the pushrod legenth due to the extended size of the lifter, but as i look at the lifters side by side of a stock hydraulic and a hydraulic roller, i see no hight difference in the plunger. does anyone have any expierience with these cams ?? this would be my first.. and am ready to fire within 4 or 5 days here..  

A friend came over and ask if I had any pushrods, I had a set of harden pushrods, so I gave them to him. He came back the next day and ask if I had any screw in studs, cause he broke one. I gave him one, but told him it was not normal to break studs on a stock motor, something had to be wrong. He broke two more studs, and did not want to over stay his welcome, and went to local speedshop for replacements. While there, they told him he had the wrong push rods. He came over and told me I gave the wrong pushrods, I check my drawer, and my .100 long ones were still there, so I told them they were stock length SBC, he replied they were to long for the roller hyd lifters. I told him you never mentioned roller hyd. I told him I would have sent him to a parts store, cause I deal very little with those motors, and would not know what push rods it takes. So if you start breaking studs, then check the length and use correct length push rods.  

You could see if a 1985 engine has a different pushrod then a 1988 . In the clevelite books we had at NAPA it would state  Roller cam on some of the parts . Or the roller engine would have its own catagory for parts . But my reccomendation would be to try and get ahold of the cam manufactor. The broken stud thing puzzles me < wouldent the pushrod bend before the stud breaks? Remeber the deal with hardened pushrods with guide plates. Would the stud breaking have something to do with long slot rockers?  

The broken stud thing puzzles me < wouldent the pushrod bend before the stud breaks? Remeber the deal with hardened pushrods with guide plates. Would the stud breaking have something to do with long slot rockers?

It had roller rockers. Regular push rods would bend or break, harden push rods put the load on the stud. The weakest link would give.

If you measure the length of the GM factory flat lifter/tappet and roller lifter you will see that the GM roller is about .6 inch longer or taller than the flat lifter. This requires a pushrod that is .6 inch shorter than engines equipped with flat tappet cams. Now this applies only to GM roller lifters, aftermarket roller lifters are shorter and will function in a flat tappet block.

The GM hydraulic roller lifter also requires a block with raised lifter bores and with 3 cast bosses along the main oil galley that mount the spider that holds the lifter alignment bars. This is unique to GM roller cam engines and dissallows putting GM lifters into a non roller block. 

Bogie