I just recently fired the engine on my 70 Cutlass after rebuilding and installing. Problem is that I can hear lifters tapping on the right bank. The stock heads are non-adjustable and only have the retainer saddles holding the rockers and rods in place.

The engine was rebuilt at LenMar Motor-sports here in the Dallas area. I wanted them to mount the heads and install new push rods. Long-story-short, the heads were not installed and I needed to spec out the rod lengths; the heads were resurfaced. I called in my rocker clearance gaps to the engine mechanic with 8.250 push rods and he ordered the new rods. Odd to me- some of the new push rods were 8.20 and some were 8.25 The mechanic said that is normal with Olds, Pontiac and Buicks. He instructed on the proper rod location for the different rods.

Now I hear this tapping on the right bank. I just recheck my rocker gaps with the piston at top of compression stroke with both valves closed.
No2 in .016 ex .010 with 8.20 rods on both valves
No4 in .120 ex .005 with 8.25 rod on intake and 8.20 rod on exhaust
No6 in .108 ex .120 with 8.20 rods on both valves
No8 in .018 ex .114 with 8.20 rods on both valves

Any help or advice is greatly appreciated.
Tony

 

If it were me, I'd pull the intake manifold, and the valve covers.

Then I'd use the stock pushrods and these pedestals and straps. http://www.autozone.com/autozone/cat...questid=501384

They are steel pedestals and not aluminum like the stock ones, so you can shim the bottoms of the pedestals up with washers until your lifter preload is correct.
I run 0.025-0.035" preload on all the lifters. You can check the preload with a 90 degree feeler gauge between the retaining clip, and the plunger cup.

How big is the cam?

 

Also, what is the oil pressure at? be sure your machine shop didn't leave an oil gallery plug out and the lifters aren't getting enough oil.

 

The oil pressure is up at 40-50 at cursing rpms and at 25 at idle.
I’m running the stock cam, as original. I should not have to pull the intake just to add new rocker guides, should I?

 

You will have to remove your intake to set your lifter preload.

 

Also, another thought, the stock head gasket is probably around .017" thick, and the aftermarket gaskets are .040"
When your heads were resurfaced, your machinist should have milled .023" off of the heads to maintain the stock compression and lifter preload. If more than that was milled, you need to shim the pedestals up. If less was milled, you need to machine the pedestals down, or mill a little more off of the head.
Since it is a non adjustable valvetrain, you need to adjust everything accordingly to the new changes made.

 

You also might consider the comp camp adjustable roller rocker arm kit, I know couple of guys who have used it on their olds and are very happy with the results.

 

Double check those numbers. You may have a cam lobe starting on a ramp with the way you are checking that.
When we adjusted valves on our solid cam race engines, we would always make sure that the lifter was on the heel of the lobe. To check the intake, rotate until the exhaust is JUST starting to open on that cylinder. To do the exhaust, get the intake to where it has JUST closed.
MEASURE YOURS AGAIN. BE SURE.

You may have to shorten the fulcrums a bit, but you need to do this an exact amount, to get your preload correct.
ALL of the available fulcrums are hardened aluminum (sorry J- those have a steel bridge, the fulcrums are aluminum), have this job done on a mill, or a precision device.
Yes, it would be preferable to get a shorter pushrod, but not for part of the engine.

Like J said, head gasket, milling, and a unknowing grinder has contributed to this.
Get .020- .025 preload. Check the preload by using the feeler gauge between the fulcrum pedestal, and the cylinder head while you tighten it down (only tighten them down whilst the cam is not on lift).
Jim