| |
Click on image for the lowdown. 
====
| | | Forums66 Topics128,111 Posts1,056,258 Members48,437 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Nov 2010 Posts: 21 Wrench Fetcher | | Wrench Fetcher Joined: Nov 2010 Posts: 21 | I inherited a 250 six in my '55-2 GMC and have added a Holley 390 and headers...I am using ported vac. for the stock dist. it seems to run better than manf. vac....What total advance should I shoot for ?
Bear | | | | | Joined: Dec 2003 Posts: 2,733 Shop Shark | | Shop Shark Joined: Dec 2003 Posts: 2,733 | It depends on many things of course (cam, ignition system, etc.) but total advance will probably be in the 35 degree range, give or take a smidgeon. Does it have a HEI? | | | | | Joined: Nov 2010 Posts: 21 Wrench Fetcher | | Wrench Fetcher Joined: Nov 2010 Posts: 21 | Nope...Just a standard dist. and don't know about the cam...stock probably...when I got it there was a 1 brl and stock intake and exhaust manf...,but it had about 5k on a rebuild...I am not sure what year the motor is...compression was 110 all across...I could get some casting ,stamp numbers and throw them out for id if needed...
Thanks,
Bear | | | | | Joined: Feb 2000 Posts: 5,219 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 5,219 | A 250 is a 250 no matter what year, they were all the same with the same heads and compression.
Depending on your fuel supply in your area, 34 to 36 total timing is about right, if you have crappy gas, back it off a little. I could never get mine to ping since the compression is 8 to 1. so set it at 35 total. I could go higher, but it didn't run any better. It runs just fine where it is, couldn't tell you what it is at idle, don't really care, thats not where it matters.
Joe | | |
|
|
| |
