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Aluminum 383 going together, measured for pushrod length and have come up with varying lengths again like the last time I did this with the old LS1 and these PRC heads. I measured all of them using the two different methods (rocker arm bolt "turn method" and bringing rocker arm to zero lash with pushrod checker and adding preload after) Using the pushrod checker to figure exact length on each seems more precise but it has also given me a variance of .020". Nine of them are 7.225, four of them are 7.215 and three are 7.235. I'm using Johnson 2110 lifters which ask for .035 preload +/- .010". I've talked to Johnson before and they stated with an aluminum block they like to see more preload (.050) since the block will grow roughly .015" at operating temp. So I'm shooting for .050 of preload, but my dilemma is you can only order pushrods in .025" increments, so if i use a 7.275" pushrod the 3 measurements above of 7.215" will end up with .060 preload on those lifters. And the alternative of using shorter 7.250" pushrods leaves me with only .025 preload on the three 7.235" measurements which will end up being less when the engine is warm. And ordering a few shorter pushrods wont do me any good either since a 7.250" won't give me enough preload on those three lifters. Also not looking to order custom length rods either. So is .060" preload too much for these Johnson 2110 lifters? Will that extra .010" really matter once the engine is warm? I always let the car idle and warm up before driving it anyway.
When doing short travel lifters you need to get custom length push rods from a place like Manton. They will ask you questions and factor in growth of block and things like that. They will also want to know what checker tool you are using because the tool itself does not have the same rod end shape as the actual push rod so that needs to be accounted for as well. Give Manton a call and they will take care of you.
When doing short travel lifters you need to get custom length push rods from a place like Manton. They will ask you questions and factor in growth of block and things like that. They will also want to know what checker tool you are using because the tool itself does not have the same rod end shape as the actual push rod so that needs to be accounted for as well. Give Manton a call and they will take care of you.
These aren't short travel lifters, these are the 2110 not the 2110R which are reduced travel. They're just "slow leak down" drop in lifters, and are .045" taller than LS7s.
Aluminum 383 going together, measured for pushrod length and have come up with varying lengths again like the last time I did this with the old LS1 and these PRC heads. I measured all of them using the two different methods (rocker arm bolt "turn method" and bringing rocker arm to zero lash with pushrod checker and adding preload after) Using the pushrod checker to figure exact length on each seems more precise but it has also given me a variance of .020". Nine of them are 7.225, four of them are 7.215 and three are 7.235. I'm using Johnson 2110 lifters which ask for .035 preload +/- .010". I've talked to Johnson before and they stated with an aluminum block they like to see more preload (.050) since the block will grow roughly .015" at operating temp. So I'm shooting for .050 of preload, but my dilemma is you can only order pushrods in .025" increments, so if i use a 7.275" pushrod the 3 measurements above of 7.215" will end up with .060 preload on those lifters. And the alternative of using shorter 7.250" pushrods leaves me with only .025 preload on the three 7.235" measurements which will end up being less when the engine is warm. And ordering a few shorter pushrods wont do me any good either since a 7.250" won't give me enough preload on those three lifters. Also not looking to order custom length rods either. So is .060" preload too much for these Johnson 2110 lifters? Will that extra .010" really matter once the engine is warm? I always let the car idle and warm up before driving it anyway.
There's only one way to measure for correct pushrod length, and that's with a pushrod length checker, which you've done. Trust it's readings/measurements. You may end up buying a few custom length pushrods. All ($$$) part of engine building......
Last edited by grinder11; Mar 8, 2022 at 10:46 AM.
Manton will get them the closest, I checked all my pushrods 11 or 12 different lengths can’t remember. I used a calipers and provided that length to Manton. I used a comp checker to get zero lash and measured end to end adding .035 to each.
Manton got them all within .007 of what I ordered. They grouped the sizes together to reduce the number of different lengths.
I ended up ordering 11 more for my own sanity was shooting for .035 +/-.005 they are all within that spec.
I was rewarded with a quiet valvetrain though.
Last edited by jasons69chevelle; Mar 8, 2022 at 07:54 PM.
There was a write-up on here about a LLSR setup...the guy cut the pedestals in sections of two rockers, then used shims under the pedestals to set his preload. You can buy the longer pushrods and shim up the ones that need less preload.
There was a write-up on here about a LLSR setup...the guy cut the pedestals in sections of two rockers, then used shims under the pedestals to set his preload. You can buy the longer pushrods and shim up the ones that need less preload.
Or buy adjustable rockers.
Or buy individual length pushrods.
I believe the drawback to using adjustable rockers is their added weight, IIRC. But it would be on the pushrod side, so maybe it wouldn't matter??
The main drawback I've seen to the adjustable rockers is the price. Jesel, T and D, Crower look like 1300 - 1900 per set. Even the Harland Sharp are about 800.
There was a write-up on here about a LLSR setup...the guy cut the pedestals in sections of two rockers, then used shims under the pedestals to set his preload. You can buy the longer pushrods and shim up the ones that need less preload.
Or buy adjustable rockers.
Or buy individual length pushrods.
This was my other idea, although I wasn't going to cut the rocker stands since they are pretty flexible, and I would only use a .010" shim under a few rockers to reduce that preload slightly. I think I may try it out and check it again as well as the rockers on either side to see if it changes the preload on those also.
edit: Just spoke with Johnson again, they told me .060" preload isn't an issue with these lifters since they have .200 of travel, so long as you have enough PTV clearance. I checked PTV with 2 lifters rigged up as solid lifters, and I had .200 clearance, so no issues there.
As others have already said. You can order whatever length pr you need from manton. If you have went thru and double checked your work and trust your numbers, give manton a call and they will get you sorted out.
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383, pushrod/johnson lifter preload question 
