Brad Penn 20W 50
Or Cenpenco 10W 40 or 20 W50

Done one Blown injected on Alky at 1500HP

I rather run Alky on carb than injected myself because it easier to tune in. You will gain about 15% more on horsepower.

Copper head gasket is nothing but trouble when running water in the engine..

What engine are you running????

Sounded like your cam timming is way off can cause the valve hit the pistions.
If the cam is too far advance the valve will hit on open side.
If it to far retarded the valve will hit on the closing side.

I would run a stepup headers start out at 1 3/4 step up to 1 7/8.

Ad Dur.288---296 Dur At .050 256---264 Lobe center 106 Lift 638---638--- Here a good roller grind..

When retarding the cam be sure check the piston and valve clearance,

I use the rotary table with lathe chuch on the milling machine.

I use an allen head bolts on all of the engine that I build with Alum heads. They are heat treated to same toughness as the ARP bolts.

You also need cooler spark plugs to run on Methanol

Hamburger Pan is the best pan for drag racing.
http://www.tdperformance.com/hamburgers_dir.html

I've had that happen on a dirt late model on Alky and it started to shut down about the middle of the straight away. Then I remove the foam before the before the next race (same night) and it ran great rest of the night.

For High rpm I use .025 gap on the plugs