RPM Question
 

When I put the truck in gear the tach drops 500 to 600 RPM. What would cause this much of a drop? I have to idle at 1200 in order for it to run in drive. I am running a ZZ502 that has a pretty lumpy cam. Is this normal?

Thats normal with a big cam. A higher stall converter will take care of that problem.

What stall should I run with this engine? I have 3.42 gears.

Youve got a huge amount of torque with that thing. You really dont need much above 2500 stall speed. Stock being more like 1600 or less. I think I'd look at the B&M nitrous holeshot 2400 . Your'e going to want a quality unit for that BIG big block and the nitrous holeshot should handle the extra power . It also has an anti baloon plate. Summit has them for $309 PN# BMM-20480

Just make sure your cruising RPM is higher than your stall. If you don't, you'll burn up your tranny in short order.