I've been trying to get my Barry Grant Speed demon (650cfm, Vac sec, elec. choke) tuned right, but it seems to always be running rich, but when i try to lean it out, i start getting lean pops. I thinking about putting some smaller jets in and was wondering what size jets came on the carb when i bought it (New, couple months ago), and what size i should look at getting. The motor is a 327, stock heads(not sure which ones), a mild cam, RPM Airgap intake, MSD 6A box, Blaster 2 coil, pro-billit distributor, hooker comp headers. any help would be great. thanks in advance
- Eric

I'd trade to some unsuspecting car guy and buy a Holley...but if thats not an option you can go to www.barrygrant.com (http://www.barrygrant.com) and look it up.

What is your timing set at?
Are you using manifold, or ported vacuum for the vacuum advance on the dist?
How much MANIFOLD vacuum do you have at idle?
What power valve is currently installed?
Do the idle mixture screws seem like they don't make much difference? (engine should die if they're turned all the way in)

i need to get a vaccum reading off the manifold. The Power valve is a 6.5 STD. i just relized that could be my problem. Is it possible i am bypasing my idle feed circut and the PV is opening too quicky? Also, when i do get the Vaccum reading ( Hot idle in gear i'm assuming) What power valve should i get. I think BG suggest 2 below the what the manifold vaccum is? Does that sound right? Timing is set at 14 deg BTDC

I think I'm having the same problem, I'm going to a 4.5 p/v on my 850 cfm Mighty Demon, we'll see what happens. Should be doing it this wednesday, I'll post the results wednesday evening.

sounds like a plan graemlins/thumbsup.gif

Doesn't really need to be in gear as long as the engine is warmed up and the timing is set correctly.Power Valves come in .5 increments like 6.5,5.5,4.5 etc. I like to go smaller on the power valve and then jet up as needed...