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I ordered a set of Crane full roller rockers for another project, but they came in with the wrong shaft diameter. Too small. But they are the right size shaft for my L98 in the 88 Vette. The seller gave me a big refund (rather than wanting them returned) when I pointed out their error, so I basically got them for not much more than the price of shipping. They're stock ratio for an L98, so only real gains will be a bit less parasitic loss, full roller tip on the valve and maybe a bit less engine oil heating from the roller fulcrum and tip. Basically, it's one of those "better than whats in there and it costs me nothing" type of situation.
Problem is they are not "self guiding", they need guide plates. My understanding is the stockers have guide plates in there, but the plates and pushrods are non hardened.
By another happy coincidence, I just happen to have an unused set of hardened guide plates gathering dust on the shelf. More leftover stuff from other projects.
Same with valve covers, a set sitting on the shelf, unused. They're not center bolt covers, but I've got a couple center bolt to perimeter bolt plates as well. They even kind of look like the stock L98 covers:
Well, kind of, but not exactly. Whether or not they will clear that wiper motor is another story.....
So I need hardened pushrods.
Question is: do I have to measure new pushrod lengths or can I just order new hardened rods in the OEM lengths?
I'm a little unsure which way I need to go because I've never dealt with hydraulic roller lifters and the need for them to "pump up" to work right. I've changed solid lifters before and have always measured for new pushrods, but how do you measure pushrod length for a lifter that "hydraulically adjusts" as it runs?
I don't think, looking at the picture, that it will. I could be wrong but to take the passenger side valve cover off, you have to move the AC compressor and it doesn't just fall in.
So first off what year car. The L98 to the best of my knowledge uses self aligning rocker arms, not guide plates. However, early cars with iron heads used slotted guides in the head and regular rocker arms. I may remember that wrong. I know for sure the l83 engine was that way and I'm almost positive the 85 was the same as well being the major change was the induction.
I think stock length pushrods will be fine, especially with the replacement rockers being stock ratio. The rocker arm nuts on these SBC engines are adjustable. You take up the slack against the lifter plunger to zero lash, then tighten a 1/4 to 1/2 (whatever your preference is). That extra 1/4 to 1/2 turn is called preload. From that point the hydraulic lifter just maintains the proper adjustment and the preload is there to fill in for wear as the mileage accumulates on the engine.
So first off what year car. The L98 to the best of my knowledge uses self aligning rocker arms, not guide plates. However, early cars with iron heads used slotted guides in the head and regular rocker arms. I may remember that wrong. I know for sure the l83 engine was that way and I'm almost positive the 85 was the same as well being the major change was the induction.
You know where to position the lifter on the cam then
So when there is no up/down slack in the pushrod give it another 1-2 turn or so, done.
Dont like the "til the pushrod doesnt spin" it doesnt always work .
Dont see why a stock length pushrod couldnt be used. You havent changed anything other than the rocker arm
Stock cam? I wouldn't worry n just use stock length pushrods, the rockers may be slightly diff but it's not like your changing multiple things IE heads, cam, valve length, head gasket, machine work n so on. I ran 1.6 stamped rockers with stock length moly pushrods & hardened guideplates for awhile on my 86, being the only engine mod. Are these used rockers or new?
Check what ever brand you get, there are three ways used to measure a pushrod and diff brands may say the same but be actual diff lengths.
The valve cover will hit the brake booster, did the same on my 86 with an adapter and proform covers that look like those https://www.proformparts.com/product...-logo-sb-chevy Had to notch and weld the cover to clear. Not sure on fronts, I got rid of my AC and air pump but if I rem right when researching it out long ago they prob will hit.
L98 full roller rockers, pushrods?
