Engine assy ??? Guage ????

[kingjr]

My 71 chal R/T w/383mag is nearing completion and I have some questions for for you mopar gurus!
1st, I had the stock 906 heads shaved 15thou and used the 20 thick steel head gasket = -35 thou off the heads. Can I bolt it back together as is? The flatop pistons are not at zero deck, they are about 3/16 recessed in the bore. Will the valve train need shimming or am I ok due to the hyd. lifters? The cam is a CompCam CC300h8, its an old grind w/pretty good lift and duration. Also, will the steel head gasket seal well or does in need additional sealer? Any other advice is appreciated.
2nd, I would like to replace the guages in the rally dash with autometer sport-comp, does anyone make a kit to fit these ebody dashes? I don't want to hack mine up as everthing works and it is original.
Thanks in advance for your help! <><

[BB 70 Challenger]

Hi everybody !!!

You may use spray can copper sealer from VHT for additional proof with the steel head gasket.

I had my heads shaved and flat, but the block surface wasn´t touched. I asked a racer buddy the very same question back then that you have got now. He just told me to spray the gaskets just before the assembly with that copper paint and install when still sticky.

Don´t know if it was useless, but worked all right for me anyway.


And to that valvetrain geometry and hydraulic lifter preload problem: shim the rocker arm shaft up (Mancini Racing still sells those Mopar shim kits) or get adjustable pushrods (Mopar has got those too...) to end up with the proper lifter preload as suggested by your cam manufacturer.



Just my 2 cents, - BB 70 Challenger

[JANDJ]

ARE YOU SURE ABOUT THE PISTONS BEING .187 IN THE HOLE? THAT WOULD MAKE YOU COMPRESSION 6.75 WITH AN OPEN CHAMBER HEAD? JUST DOUBLE CHECKING.

[kingjr]

No JandJ, I know that they are not at 0 deck, my measurement was a guesstamet! So I definately need to shim the rockers? <><

[WS23]

KingJr,

My opinion is no shimming is required.

You said "I had the stock 906 heads shaved 15thou and used the 20 thick steel head gasket = -35 thou off the heads." What are you talking about here? How do you get 35 thousands off the head?

You only took off .015 of an inch off the head. The big blocks came from the factory with steel shim gaskets with .020 crush. So the only thing you are dealing with here is the .015 you took off the head. That does not warrant having to shim the valve train nor getting adjustable pushrods. Think about it, a Fel-Pro composition head gasket is approximately .040 crush. That's .020 more than the stock steel shim. Does that mean that when you replace the steel shim with the composition you need to get adjustable pushrods or shim the valve train. That is a loaded question, the answer is no.

As far as the steel shim gaskets sealing, they have worked well on countless engines for 20 years & more. However, understand that when these motors left the factory they had a machined true surface on the head AND the block. You didn't say anything about your block deck being trued or shaved. I personally will NOT use a steel shim gasket unless BOTH the block & head surfaced have been trued.

Good luck with your decision.

[kingjr]

ws23, thanks for your response. The reason for my concern is that the motor had the 40thou crush blue permatorq and I replaced it w/the 20thou steel =-.20. My deck was not machined only the heads were shaved .15. That is how I got the .35thou. Do you feel the same w/these #'s. Let me know, thanks. <><

[WS23]

That's what I figured. You will be fine.