Guess no one wanted to touch the header one. Sorry I should introduce myself, forgot I'm new because I've been checking these forums for months, lot's of good info. Finally, because I finally got it, 70 chevelle ss396, aquired in march as a basket case. shouldn't call it a basket case but that's how I got it home, in baskets, boxes, pickup trucks and a trailer. it's all back together and on the road now. need advice on timing. have to move the distributor, could just put it back to where it is now but thought i'd ask the experts. new pistons a few years back, don't know specs but compression can't be too high. runs on pump 93 no problems. cam gross lift .526 duration 230 at .050. any other details needed, oh 4 speed. thanks in advance

Welcome aboard graemlins/thumbsup.gif
I would go for 16-18* base,36-38* total by 3000 rpms.

thanks! it's sitting at about 16 now, after rebuilding centrifugal advance. only checked at idle, just a basic timing light, no dial back.
BTW, found paper work on pistons. forged alum TRW .060 over, .182 dome. so experts what does that mean? compression wise. :confused:

Originally posted by Finally:
BTW, found paper work on pistons. forged alum TRW .060 over, .182 dome. so experts what does that mean? compression wise. :confused: Thats the smallest dome 396/402 piston available,basically about 9.5 to 1 w/closed chamber heads (101 cc's) or about 8.5 to 1 w/open chamber heads (119 cc's)
Do you know what head castings #'s you have?
The .182 dome basically came in all 396/402 65-72 unless it was a 375 HP motor,which had bigger domes.

ignore previous post, i didn't give enough info for somebody to answer. not sure about the heads, have to try and read casting number through oil filler. is that possible? then i can find out compression. see i'm not a total idiot, just a partial one. redface.gif

see you responded while i was typing. thanks for the info, i'll try to get casting numbers, mostly for curiosity sake. just like to know what's under the hood since i know it's NOM.

I would remove the valve cover to save your sanity smile.gif

mr 4 speed
since I already started might as well show a little more of my ignorance. you said total advance 36-38*, when you say total you don't mean with vacuum do you? maybe you do, i would guess you could get that with just centifugal at 3000 rpm. :confused:

vacuum advance will add about 10* to the 36-38*,but you don't have vacuum advance at WOT.

So the 36-38 at 3000 is without vacuum correct? Just want to be sure. Have other springs for the centrifugal advance, curve graph shows those springs will provide about 20* at 3000 rpm. So I guess I need to use those, I started with middle set of the 3 they provided so I'm not getting an additional 20*, total of 36-38* at 3000.

Please let me know if I'm understanding you guys correctly and thanks for all the help.

yes,that is correct.The 36-38* total by 3K is w/o vacuum advance.

mr 4 speed

thanks again, i'll see if i can get it set up as you suggest