i got one. but my block has a xtra water hole. 2 on one side 1 on the other. 2 are the same size but the 3rd is like the size of a pen.
what should i do plug it with j.b weld or some thing like that. or just not run the pump.

 

That small port on the right (passenger side, beneath the large sized hole) is a thermostat bypass port. When the thermostat is closed (engine cold), it allows coolant to circulate within engine, to help prevent any localized overheating. This port can be tapped out (I believe an 1/8" NPT tap will work) and a pipe plug installed. If you do this, you should drill several holes in your thermostat (usually 3 or 4 equally spaced 1/8" holes in the flat portion around the opening) to allow coolant to bleed past the thermosat when it's closed. This will simulate the factory bypass system, and also (with the block port plugged) won't allow hot coolant to recirculate through your engine after the thermostat has opened.

 

thanks for the help. i also would like to know how much nos you think a stock bottom end would handle. i got a 2bolt sbc 355. 10.0:1 kb piston, Speed-Pro Plasma-Moly rings. comp magmun 280h cam, comp roller tip rockers, Edelbrock Performer RPM
intake, Holley 750cfm Vacuum Secondary, stock heads that were mildly ported just cleaned up.

 

How much? Good ignition, good fuel, good tune, you'd probably be able to spray more than you'd ever want to without breaking. Buddy of mine has a motor very similar to yours he was hitting it with a 200 shot for 2 years and it never blew up ...Remember its all in the tune and quality of your ignition.

 

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