exaust glow

[DaveBauerSS6]

Renegade makes a 98 octane and a 104 octane race gas...Chad probably doesn't like the pump gas because of the inconsistency you get...I guarantee you that you will see more HP out of lo compression deal with 98 octane than 110 octane...non oxygenated fuel...apples to apples..Seen it numerous times on a dyno..

A few years ago I ran in Tina Mcgowens 350 hobby motor ( 180 cranking compression rule, stock heads, hyd cam, on a 2 bbl) at Watkins dyno on racing gas and regular 91 and the chart lines overlayed so well you couldnt see the difference. The numbers were the same. He recommended pump gas for those engines. All my hobby and american stock motors run on pump gas, making good power and living.

[DaveBauerSS6]

We are running a 350 engine with a holley 500 two barrel, 450 lift cam, 36* of timing, after ten or so laps into the race the exaust starts glowing, we went up in jets and are running 78's now, was told it could be a vaccume leak but changed the intake and still doing the same thing, plug check looks perfect, any ideas?

What intake are you running? Normally a vac leak will sour the idle and give you a clue.
You said you went up in jets, what did you start with, and you said the plugs looked perfect??
Did they look perfect before and after the jet change?

If so I would go with Bush suggestion on timing. Verify the timing mark on balancer and pointer. Verify the total advance at rpm and try another distributor if the problem continues. The module could be miss firing and sending out unburnt fuel. Lost a motor recently due to 7 and 8 crossfiring due to the module. This was verified by the manufacturer.

I ran into this only once, but check the exhaust system for a large restriction.

[Racingtech]

Fuel burning in the exhaust can cause the exhaust to glow. How it gets there can be caused by several things, To rich , miss fireing, if you are running a HEI ign, check your coil they can overheat and burn up and the same thing can happen to the module. Causing low fireing voltage, and fuel not being burnt in the cylinder, and being pushed out into the exhaust. I have had this same problem in the past. I think looking at the fuel causing this is a long shot.