Timing a rebuilt 318.

[AmadeusCharger500]

74 318.
302 Heads, edelbrock performer intake, edelbrock 650 carb, 2.25 headers, 904 stock trans, 3.55 open rear, stock distributor.
MAchine shop milled the heads and measured chamber volume. Told me it would have 9.5:1 compression with a .040 gasket.
Car runs great only issue I have is its getting bad gas mileage. Its getting about 10mpg!
It is currently set at 15 initial, not sure of total. I plugged the distibutor vacuum advance.
Any help would be great since I am taking this to Carlisle this year.

[Plumcrazy]

Do the plugs show signs of a too rich mixture?

[RD]

just an observation, but those headers are HUGE for a 318!!!

[The Kid]

just an observation, but those headers are HUGE for a 318!!!

Those are huge for a 440! I'm assuming that's a typo ?

[AmadeusCharger500]

Yeah I was not thinking/typing right. I don't really even know what size they are. They are headman headers for a 318 from summit. 1.58 primaries I think!

[firefighter3931]

Do the plugs show signs of a too rich mixture?

I agree....the jetting could be way too rich, try leaning it out.


Ron

[AmadeusCharger500]

I called a shop that is known for "excellant" and expensive work. I asked them if they know about how to tune my car. They said yeah. I asked how. They said with a vacuum guage and by ear.
Hell I can do that!

So here are my timinng numbers.
5 BTDC= 15HG
10 BTDC= 16HG
15BTDC=17HG
20BTDC=19HG
25BTDC=20HG
I readjusted the idle to 800rpms after each adjustment.
I put it back to 22BTDC with 19.5 HG
I know these cars usually like 15 initial timing. Is mine telling me it likes 22 or 25? Should I hesitate for any reason to have it at 25?

The car had been running at 5BTDC for the whole while I was getting poor MPG. Will readjusting it to proper number help this?

I know the next step is jets and metering rods and reading the plugs. Can anyone tell me if my timing sounds right?