Ok, one more question on the Holley jetting.
Today I made the IFR smaller (maybe). Didn't make much noticeable difference!
I don't have the precision equipment to drill .033 instead of .034 with sufficient accuracy. Will increase the IAB slightly. If still too rich, then I'm going to make the TSR smaller.
Trailbeast, any progress with yours?
You can put a strand of wire in the IFR and bend it over. The gasket will hold in there. When you get it right you can calculate the area and drill a permanent IFR.
The more I think about it, I don't see how the AFR could ever be constant or leaning out (before the mains come in) with a big cam. Idle AFR set with the needle screws wherever it likes, as long as there's enough range, ok.
But as Mattax said, AFR richens as the vacuum rises off idle from the 7-8" idle vac, sucking harder on the t-slot and the t-slot provides more fuel from the bottom of the slot (and less air bleed at the top of the slot too).
Seems like it will be a compromise at best. If I make the AFR right with the full t-slot feeding, won't it be way too lean just off-idle, which will cause a lean stumble?
Edit: yes, I have a pin vise although I haven't tried your exact method yet.
Ok here's what I found.
I used a paper clip bent in half and inserted it into the small hole where the home made jet would go.
Two strands of the paper clip didn't make any difference at all.
Three strands barely made any difference in the T slot feed. (maybe .2 of an AFR number)
Four strands came a little closer but I had a lean flat spot just off the idle stop.
(Felt just like the pump shot not working)
For now I went back to stock and have a rich spot (9.5-10 to one) just as the throttle comes off the stop and right where my throttle is most of the time around town under normal driving.
Next will be the power valve change as
@yellow rose suggested, but I can't find my dang vacuum gauge.
I'm going to pick up another one today so I can find the one I have.:D
The one thing I don't understand is how a power valve that opens sooner as YR suggested is going to have any affect on this rich spot off idle.
So in conclusion in my case limiting the T slot and idle feed didn't even come close to fixing the rich spot.
Now I have to think it all through as to why.
It seems my rich spot has nothing to do with the T slot, but it must still be well before the main jets come in.
WTH?:D
I did swap out my 75 main jets for 68's and now 45-60 or so cruise is good.