69LT1Bird

iTrader: (1)

That is why I thought you needed to see how deep the valve seats are cut and how the valve face sits down in the seats. Also the actual milling of the heads. If the valve face sits down into the seat it will raise the valve stem. If the stem was not cut to match the difference the valve stem will be higher which could lead to this issue. Worth checking.

Here is a good article:
http://www.enginebuildermag.com/Arti...r_options.aspx

vettenuts

iTrader: (4)

Did you try it the other way as a double check, i.e., set zero lash with the plunger fully up and add the preload? Also, if the valves are indeed sunk deeper and the stem is higher relative to the rocker pad you had better check geometry prior to measuring for pushrod length. My guess is you will have to shim up the rockers to correct things assuming the valve stem heights have indeed changed.

00Wildcat

So the bottom line is the valves are deep in the seats from machine work and the heads were milled . So the rocker stands need to be shimmed along with shimming the springs to get the installed height correct and the rocker tips where they belong on the valve tip . then the pushrods will probably end up being back to somewhere around 7.375? So based on what was written above the stock GM lifter has .200" travel and .100 preload puts the plunger in the middle where it belongs?

357i

iTrader: (4)

Update:

I decided to go back to square one, so just in case, I pulled the engine and removed the heads and replaced the lifters. Put it all back together and still only have 75lbs of compression. Measured for pushrods and comes up to 7.175, that just seems rediculous to me. I guess there could be a cam issue, maybe the wrong base circle size? I wish I didnt throw away my stock cam.

It just doesnt make sense that I milled the heads .025" (yes I did check it against a stock head, its actually .026") and the pushrods need to be almost a 1/4 inch shorter than stock

357i

iTrader: (4)

An update, I bought a stock LS6 cam and stuck it in, same thing

vettenuts

iTrader: (4)

Are the valve heads recessed (valve job done on heads)?

357i

iTrader: (4)

Valve job was done(3 angle) but valve heads are not recessed. Is there anything in the oiling system that could keep the lifters pumped up to the max?

Always2Slow

iTrader: (8)

Well looks to me you checked push rod length thoroughly check rocker arm to valve tip geometry

JudgeGuns

iTrader: (1)

did you put LS6 valves in the heads? they are alot longer! even so, i would have your valve stems cut