I have a 434 carbed with a gear drive. I twisted engine to 8K +. It made a small backfire after I had let off running about 2K then died. I adjusted all valves, checked timing,new plugs. I am getting fuel & spark. MSD dist, 6al & retard box.there is no back firing or popping thru carb.Is it possibly for a gear drive to jump timing.Engine will not start. I'm looking for a simple solution before I start tearing engine down.

 

Pete Jackson gear drive? no. straight gears, where cam turns backwards? no
to check timing:
put engine on TDC, pull left rocker cover, pull dist. cap.
1. both rockers on #1 cyl. will be easy to move, meaning both valves closed.
2. dist. will point to #1
3. if eng. will not run,
remember you need 4 things
a. fuel
b. spark
c. compression
d. starter / rotation
take the msd box off, and try a stock dist. your dist gear may be the problem.
I had a similar experience with a 327, and the coil wire wasn't crimped right, and it lost continuity.
I also had a engine quit like yours, and the wire on the points rubbed the breaker cam and shorted out.
I had another car that the ground wire inside the distributor wore out and broke. when the vacuum cannister pulled the breaker plate, the breaker plate lost it's ground.
I had a MSD distributor that a hall effect generator inside it. It would not start when it was hot but was fine when started cold, and ran fine till you shut it off.
what kind of distributor? HEI? or small diameter inductance type?
look inside distributor cap to make sure the button is still in the distributor cap in the center.
It sounds like you have spark, but it's not there when cranking.
if the timing was off, it would spit back out the carb.
at the very least, pull the rocker covers, crank it over, and watch the valves move. if there's a mechanical problem, the valves won't operate like normal
Do you have a resistor on the coil? do you have an ignition circuit that uses a resistor in the ignition?
pull a couple plugs and check that the pistons didn't smash the electrodes due to rod stretch
check, check, check, check

 

you may have a dist. gear pin problem

 

All new plugs, old 1s were gassed out. I changed from #86 to 82 jets 750 mighty Demon. I ran a compression check 190-195 lbs good on leak down, only 200 mi.on engine 12.8 comp. I pulled VC all seem to be working ok, readjusted lifters. I am using a MSD with crank trigger, no resistor in ign. new power master starter, new 00 battery cables, 115 racing fuel, just checked dist. gear OK,

 

Check the spark with a timing light to see if & when it's firing the plugs.