John, Thanks for the quick reply! I had read posts at other places about vacuum at idle, but none specific to the 261 w/ an M4F. I have adjusted the mixture as you said and it seems happy at 2.5, maybe a little less. Nothing I have done (timing,lash,idle, mix, etc.) has changed the vacuum enough to leave it changed. The vacuum pulls down to 3 and up to 21 when I snap the throttle and will do 16 at 2000 rpm. Its pretty steady too, with only a slight twitch at idle. Anyway It does pretty well as far as I have run it and I think it should get better once it sees some good road time. Thanks again!
