i have a 79 one ton, crewcab, 4x4, 350/400/203. it has a newer starter (reman) and brand new optima, the cables are in good shape. it cranks very slow (extremely slow) for about 5-8 seconds and then starts. i have no idea where i should start. can anybody give me any suggestions? thanks,
chad

Have ya been messin with the distributor?
Hard and slow cranking is a sign of to much initial advance.
Or the mechanical advance is stuck wide open.
If you have not been messin with the distributor then pop off the cap and see if the rotor turns freely.
If the rotor is hard to turn or will not turn at all then the distributor needs to be pulled, disassembled and cleaned.
After awhile varnish builds up and will keep it from moving freely.
Or the timing chain is so wore out that it slipped and advanced.
A quick check is to loosen the distibutor and turn it counterclockwise just a little bit (retarding) and crank it over, if it starts easier then the distributor is the culprit.

Sounds like the timing needs to be set right. I 2nd the cleaning too......:D :beer:

Still could be cables, or bad ground between the block and chassis / battery.

i would definatly check the timing.
if its advance a little too much,
it will drag when trying to start

I'd go for the timing too. Had a beater years ago that had a bad timing chain so if it stalled when the engine was hot it acted just like the battery was dead. If I gave the dist. a little twist she'd start right up.

one more vote for timing.