i was having problems, well not really problems last year with popping out the exh, i was continuously leaning my kits all last year, finally pinched a ring at the end of the year. Well upon rebuilding the engine, i have found that the bronze gear on my oil pump drive is worn big time. So much that you can move the rotor back and forth almost .125 !!! Needless to say, when you put a timing light on it, it retards about 6-8 degrees as you increase the rpm. Now this may not have been a bad thing and caused any harm to the engine, BUT now i know that when i replace it , the timing will be where its SUPPOSED to be. SO im going to lean it out, spread some jets and see just how fast i can go this year....
Thankfully the timing was RETARDING instead of advancing LOL...well the gear is only 15 years old, dont they last forever????

Timing caused some problems with me this weekend also..I have a adjustable retard box hooked up to my 7al3 and I went to the line to make a pass and when I lifted my finger off the transbrake button it spit and sputterd and fell on it face..found later on that my retard box took almost 20 degrees of timing out of it

pulled a plug and it was beat red!!!..pulled the box off of it zero'd the the main 7al3 box and manually adjusted the crank trigger and timing was right on at 28 degrees..when I first fired this motor in the car last weekend the timing was jumping all over the place..

I was very nervous that it advanced the timing..the way this motor is setup... it could burn some pistons without any nitrous

Guys go to a crank trigger than these problmes stop. When you set timing and go from Dist, to dist gear to camshaft to timing chain to balancer its going to move. Put a crank trigger on and forget it.

Herb jr