What is the height from the centerline of the wrist pin to the top of a stock slant six piston? Is there a difference between the 170 198 and 225 pistons? Also can anyone tell me how to degree a stock cam without having any info on it?

wtzupdoc@pmcol.com

1.765 for 60-76 "factory" units, 1.740 for "replacement" pistons
:
: Is there a difference between the
: 170 198 and 225 pistons?

No, None, Nada, all SL6 pistons are the same basic 3.400 size.
:
: Tell me how to degree a stock cam without
: having any info on it?

All you can do is "split the overlap", here is an old post on the subject. More can be found using the search function.
DD

There is a way to "splite the overlap" in order to quickly check the position of the cam.
Here is a post I pulled-up from below. It reviews a quick way to check the cam position :

Posted By: Doctor Dodge (Doug Dutra)
Date: Tuesday, 6 February 2001, at 1:39 p.m.

In Response To: Whoa! Compression! Pease help! (Mark W. Marasch)

Mark,
I keep thinking about something you said in a previous post:

*"I've centerlined the cam at 103deg (too advanced?)"*

My thinking is that you should re-check your cam timing at the valves, lets see how close your cam position is to a true "split overlap" setting. here is my "quick & easy" check process:

-Pull the valve cover, install a "degree wheel" or accuratly mark you damper.

-Rotate the engine to true TDCE (Exhaust Stroke) (TDC point with no "lash", both valves hanging open on "overlap")

-Place a dial indicator on the intake valve keeper. From TDCE (zero) rotate engine backwards untill the intake valve closes, (dial needle stops moving)"Over shoot" and come back to this point, turning clockwise to where the needle starts to move again, note this position in degrees.

-Move the indicator over to the exhaust valve keeper. Now continue to rotate clockwise, through TDCE and to the point where the exhaust valve closes. Note in degrees where ex. valve closes.

-Subtract the small number, TDCE to intake opening (intake Pre-TDCE opening degrees) from the total overlap number,(degrees both valves are open) the remainder, (exhaust Post-TDCE) should be 4-6 degrees less then the intake Pre-TDCE number. Example: intake opens 26º BTDCE, exhaust closes 22º ATDCE, (48º "travel" or total overlap) This would be a 2º advanced cam

If you see that the "split" is pretty even, with the intake opening a few degrees longer, then the cam position is OK. If the exhaust is staying open longer then the intake or if you see the intake opening more the 10º longer then the exhaust, you should re-degree the cam.

Note that these measurements are taken right off the valve "keeper" at the proper "lash" setting so we can see what the valve / engine really sees. (lash changes have a big effect on this test so be sure the lash is correct)
DD