Stock for a Hyd roller is 7.200. I found and picked up a set of TF Chrome Moly 7.250 one pieces for 12 bucks new on ebay. Would this work well in basically a standard rebuild? Will .050 make a huge differance?

 

Yes, it will make a difference. It can seriously screw up your rocker geometry. This can cause valve train issues. You should use the correct length, if you don't know the correct length, you can buy a special length checker push rod and check your set-up.

 

You're only guessing what you need. Technically the only engine that needs stock length pushrods is a stock engine with nothing more than a basic rebuild and no machine work.

The only way to know if an overlength pushrod will work is to install them and check the valve train geometry or buy a checking pushrod and see exactly what length is needed.

 

How do I mock up with a hyd lifter?

 

buy 2 solid lifters and use them for the dummy assembly