whats the safe max to take off a 360 block

[OUTLAW]

I have a spare 74 360 short block sitting here and noticed the pistons sit .080 down the bore at TDC. Since it is a 8.4 compression motor I was wondering if anyone knew the safe max that can be taken off the deck without weakening it and how much it would raise compression

[moper]

I've heard of .100 being taken off. This also neds to have the end rails cut down. But, if it's going to a bare block to get milled anyway, it's prob only a couple hundred more than the milling alone to get better pistons and have it bored and honed. The compression height of the piston is your problem, not the deck. You'll also need an intake milled to fit, and shorter pushrods or shims too.

[OUTLAW]

Trying to raise compression for a customer with out having to re balance the motor. My machinist says .020 off the deck will raise compression more than .020 off the heads will and anything over that will require the manifolds to be milled too. The end rails he says to pitch the seals and silicone them . I agree about new pistons , but around here getting a mopar balanced right is almost impossible ....infact the only shop to balance is 50 miles away and they prefer to just do chevies. Everytime I talk to them I am amazed they know which end of the crank the flywheel goes on to
My machinist says $100.00 to deck how ever much I want. vs $250 for pistons +$100 bore and hone +150-200 to re balance

thats why I was wondering about shaving the block ...would like to get comp up around 10 or 10.5  from the stock 8.4

[moper]

Um...The heads are typical mopar open chamber, yes? .020 off is .020 off. If he's running closed chambers, your guy's right. In any case, .020 wont raise it much, about .4 by my rough calculation. Calculate the real static ratio with a typical 915 head. It's really more like 7.6:1. If it were me, I'd either work with what you have, and build accordingly, or fit a set of Magnum heads to it. Dropping 10ccs of chamber size would help by about .8 .