hey people im just wondering if some one could tell me if i will need to run premium gas in my truck or what on 89 octang the engine diesels when i shut it off and if i advance the timming it pings really bad and turns over really hard im running about 12 to 1 compression a mild cam and 750 edelbrock and
headers  

I think you have way too much compression for pump gas. you might get away with premium, but it's still not gonna like it.  

yeah i kinda figured that was the problem and i just found out that i have 11.88 for compression with the 64 cc heads  

Jason, somehow your engine ended up with way too much static compression. Static being calculated as the ratio of total displacement of a cylinder plus the space above the piston divided by the space above the piston.

Most certainly 89 octane unleaded won't carry 12 to 1, even 92 won't without aluminum heads, 160 degree thermostat, rich mixture, really big cam, stiff rear gears, all the stuff that takes load off, reduces temperature of, and throws fuel for it's cooling effect at the engine.

So how about a description of what's in the engine and the vehicle? You stated the heads have 64cc chambers but nothing else. To solve this problem could be some adjustments all the way to major component replacement, but I don't know what you've got so I don't know what to recommend.

Bogie  

WELL BOGIE I HAVE SPEED PRO PISTONS 30 OVER WITH 0.275 DOMES  EAGLE H BEAM RODS 5.7 THE HEADS ARE CAMEL HUMP 202 160 VALVES I FORGET THE CAM SIZE BUT IT IS A MILED ONE WITH SMOOTH IDLE  AND I JUST GOT DONE PUTING ON A SET OF 76 CC CHAMBER HEADS AND THAT HAS SEEMED TO TAKE CARE OF THE PROBLEM IT STARTS RIGHT UP NOW AND SHUTS OFF WITH NO PROBLEMS AND DOESENT PING ANYMORE  IT SEEMS THAT HAS LOWERD MY COMPRESSION ENOUGH FOR THE PREMIUM PUMP GAS