OK I searched and searched and found nothing definitive on this: Where and what is the TDC mark on the late 261s for ignition timing purposes? Mine came out of a 1962 Chev 1/2 ton.
I just got the used 261 w/ 3 spd and OD into my 53 half ton. I'm having to rewire from scratch and got the ignition so it cranks over with key start and throws a good spark but when I looked on the flywheel I could find no timing marks that I recognized. I am used to seeing lines scribed about every 5 degrees with a larger line in the center with maybe a zero above or below it. What am I missing here?
As an alternative I estimated TDC watching #1 cyl rocker arms and that puts #1 cyl about 3-4 O'Clock position. (After reading the stuff that came up on search it seems I should have pulled the rocker arm cover and watched both 1 and 6 to be sure.)
Using starter fluid I can get popping and what sounds like one to three cyls firing but never all six smoothly. Pump finally got gas out of gas can and up to carb and the accelerator pump puts a good stream in but I cannot get it to fire at all on gas, only starter fluid.
The carb is a Rochester that has a paper tag saying it was rebuilt by Holley. The PO who pulled the 261 to install a 350 said the truck had been running fine right up to when he pulled the 261 and tranny out. Assuming it was running then--about two months ago--I doubt the carb is gummed up and the fuel filter looks OK.
Got frustrated and quit for the night before I did something really dumb. Would appreciate some assistance re. timing marks, setting up the distributor correctly etc.
Jerry
