250 HEI Timing, vacuum advance question

[felm0001]

Thank you all for the responses.

70stevebolt: yea I kept my old distributor, I may upgrade it with the pertronix and plug it back in. Depending on how well this upgrade runs.

geezer: I have the stock intake and exhaust manifold in there right now, I am thinking of upgrading and getting a quad intake and just buy a new carb. Keep this one for my kids to play with.

So I took the truck down to a "classic restoration shop" we have around here. I have been there once before and wasn't too pleased, but the main man is wiser than me, so I figured he could help.

For 25 bucks he told me that the newer HEIs have too much mech advance built in so the vac is probably too much. He set the initial to about 14-15deg and capped my vac line. I took her home and she ran ok, had some popping and putting while idling at the intersection, so I set my timing around 8deg initial advance and am keeping the vac line plugged for now. Runs strong and I took her on the hwy at about 70mph for about 10 minutes. I have the cheapest 85 +10% ethanol gas in there so I assume 14deg + some higher octane stuff would run better.

Anyway, I guess the answer is, 16deg mech + 5-9 vac advance is too much advance for my 250.