What range of length should I go for when purchasing a pushrod checking tool?

I have a 0 decked block with LE3 heads and a 1074 gasket. I am going to be checking the length so I can order the correct pushrods.

 

what are the ranges? you probly be in the 6.900 to 7.150 range

If you need the 7.150 let me know I have a brand new set of cm .083 1pc.

 

i would go for something with at least 6.5-7.5"

 

6.12-7.5 or 7.5-8.7

So I am guessing the 6.12 to 7.5 is the one then. Thanks

 

I used Comp Cams P/N 7702-1 which has a range of 6.8 in. - 7.8 in. Don't forget that when you use this tool, it should be used with checking springs because the normal valve spring pressure can collapse the threads on the pushrod checker. You should also make up a solid lifter to use for the test so the lifter can't compress and throw off your results.

 

FWIW in a similar setup to yours (same deck height, gasket, head porter) I ran 7.05" pushrods. Should give you an idea of the range to look at.

 

can you explain more on the spring? Do you use both a homemade solid lifter and a spring? Does the spring come with the tool?

 

Solid lifter is the best, you can change a hydro top a solid with very little work, test then turn it back.

I also bought a silky soft spring at a hardware store which worked perfectly as well. There was no way this soft spring would compress even a dry lifter.

 

No, the springs must be purchased separately. I used Crane Cam checking springs (p/n 99881-2) which are designed specifically for that purpose. The aren't very expensive, something like $4-$5 for a pair, which is all you need. Other companies make them as well.

It's important that you make up a solid lifter from the exact same brand and part no. of the lifters that will be actually used in the motor. Different lifters can appear to be virtually identical, but slight variations in critical dimensions exist. For example the cup depth of the stock GM lifters is quite a bit different from the cup depth of Comp Cams 850-16 OEM replacement lifters. This could really throw off your calculations if you made up a solid lifter from a GM lifter, determined your PR length and then used the Comp Cams lifters with those pushrods.

It's easy to make up a solid lifter. Carefully remove the retaining spring and disassemble the lifter. In place of the spring, use small brass washers or some other type of spacers to make up the space occupied by the spring and reassemble the lifter.