caseypryan

iTrader: (10)

My cam will clear a 59cc chamber head just for reference, and I'm wondering if I mill .020 to about a ?62cc? chamber, is that too much compression for a nearly daily driven street car in Las Vegas heat? Also will my compression ratio be about 11:1? and I want to use a stock gasket for my car. It's a stock bottom end, stock block in my 2000 SS

camz28arro

iTrader: (12)

With stock bottom end and 0.053 gasket, milling the stock 243's down 0.020 will make it about 61.6cc and give a 10.95:1 compression. The compression should make it more efficient and increase throttle response making it possibly better for a DD.

caseypryan

iTrader: (10)

Thank you very much. I thought a stock 243 gasket was .040? do you have any part numbers for the gasket? I would prefer to use an OEM gasket just so I can trust it better..

caseypryan

iTrader: (10)

Also I since I am milling it .020 should I use a 7.375 pushrod instead of a 7.400? Thunder racing said I should use the same size and the shorter pushrod may make noise.

camz28arro

iTrader: (12)

The thin cometic gaskets are 0.040 but stock the GM MLS gaskets are about 0.052-0.053, I've had bad luck with the cometics and wound recommend the GM gaskets.

Also since the aftermarket cam usually has a smaller base diameter, the 7.400 rods should be fine. I milled my 243's 24 thousandths and the 7.400 pushrods were still within the tolerances.

masterz28

iTrader: (8)

yeah good info above i recently asked Pat G some Q's got some good info from him too. Are you port and polishing your heads?

caseypryan

iTrader: (10)

No sir I am not porting/polishing. I'm not looking to spend the extra money. Do you have a part number on the GM MLS gaskets that are .052? I think it's 12498544

caseypryan

iTrader: (10)

and thank you for the good info camz28arro

AW794

iTrader: (7)

You may want to invest in a pushrod length checker. They are typically only 20 bucks from most sponsors.

caseypryan

iTrader: (10)

Can someone give me part numbers on 243 head gaskets? The GM MLS ones. And water pump gaskets (2). Also should I used the 2004+ head bolts or the pre 2004 bolts?

beedo

iTrader: (28)

Depends on what year your engine is, if its a pre 2004 it will have short bolts in the first and last middle bolt holes of the head and if its later than 2004 they are all the same lenght.

camz28arro

iTrader: (12)

http://www.thunderracing.com/shop-by...ets-and-Seals/

Same as the stock gaskets. Should be 12589226

caseypryan

iTrader: (10)

just ordered it from there. Thanks guys!