Need Some Opinions Plz! 84 Gmc Sierra

jefferias · March 15, 2008

hi all. been here for a bit now and dont post alot but learn alot here, i love it. just wonderin what everyones thoughts are. first off i have an 84 gmc sierra 2wd. i just swapped out the old ,tired 305 for a 350 bout a month ago. (just fine tuning now) the 350 was a crate tbi that i swapped back over to carb, and my v-belt setup. i re-manned the heads- grind and lap valves, decked about .0045 thou. light port work done and re-faced seats. got a eddie performer intake , msd streetfire dizzy 8362, re-manned autolite quadra-jet, swapped to a holley electric fuel system as opposed to my mech, all new seals thoughout the motor.

just wonderin if that dizzy is manifold or port vacumn? and how many mercury inches i should let through the vacumn advance. i get about 23hg at manifold port at idle. also right now im at 8btdc what you guys think about 10degrees? i also have a 1" alum. 4-hole taper eddie spacer not installed right now-should i put it on?

the truck runs strong and well just idle is a little rough,not bad by anymeans just a lil rough. WOT seems fairly good and she seems to like higher rpm but she drinks the gas. so just any thoughts or suggestions would be hgreatly appreciated. once again thanks for, well quite frankly, this whole web site.

Mike G · March 17, 2008

I think it sounds like you are pretty close to being on. Since it runs good, lay off the spacer. How many CFMs is the carb. The vacuum at 23 would be good for me. Try running the advance up to 10 and see how she behaves, you can always come back down....

--Mike

jefferias · March 18, 2008

I think it sounds like you are pretty close to being on. Since it runs good, lay off the spacer. How many CFMs is the carb. The vacuum at 23 would be good for me. Try running the advance up to 10 and see how she behaves, you can always come back down....
--Mike

I believe the q-jet is like 580-600 cfm something like that. i moved the initial advance up to ten and she likes it. tried 12 and it was no good so im at 10btdc. problem now is my vac advance on my dizzy is broke, it used to work but stopped bout 4 days ago i believe. no big deal i think i got warranty on it so its all good. i guess ill leave the spacer off for now cause i dont feel like re-calibrating everything again. thanks mike