ignition timing question 1972 400

[Fabbr]

Ive been tuning my motor up, this is a stock 400 with a 270 duration Rv cam, 625 Carter carb headers, the distributor is an original electronic type. The first thing I checked was the rpm for all in timing, it wasn't all in untill over 4k. I took it apart and removed the heavy spring, its now all in at about 2k and seems to be much more responsive. I didn't change the mechanical limit/slots. I have it timed at 16 degrees initial, all in at 2k is right at 40 degrees. I havent driven it yet but it seems to run and Rev good. The trans is a 727 with a factory high stall, 3.91 rear gear. Is the timing do-able set like this?

 

[Fabbr]

I read somewhere that a low compression motor liked more advance up to 40ish degrees..was wondering if there was any truth to it, if so I should be ok?

 

[67Dart273]

The thing is, your total may be way OVER that because most these smog dists. had a long slow advance, designed for intial timing of, hell, sometimes AFTER TDC!!!

 

[Fabbr]

Wound up to 4k its still at 40 degrees, its stable and maxed from about 2k all the way up, with the knob on my timing light at 40 its dead on zero at the balancer

 

[67Dart273]

LOL. I have to tell you that does NOT sound like a stock distributor. But if that's what it is, that's what "it is."

 

[Fabbr]

There are three possibilities, i have 3 distributors, 1 from each, 72 newport, 74 new yorker and a 77 dodge pickup. Im not real sure which one this is but they were all 400's. What do i need to watch for if somethings not right, pinging?

 

[Fabbr]

Update..after taking the dart out and standing on the gas somewhere around 4000rpm it had a really bad high rpm miss. That quickly verified that my timing readings were wrong(too much mechanical) turns out my aging dial timing light has issues. I purchased a new digital timing light and a factory reman dist..$50 from rock auto. I took it apart and welded up a slot. After pulling it and fine tuning the slot length im now at 15 initial and 38 total w/o advance, now it runs like it should. Thanks for all the input guys.