I've spent all week cussing at the air bleeds (and brpv's...which I've decided to try making)
I'm talking mostly about the lsab's
My HSAB's are blocked....which is one of the best things I've done to the carbs. I see no negative effects, but more fuel at the top end. I'd highly suggest this modification
Right now, I have an issue with too much fuel at low rpm or idle...and not quite enough up high. Typical
Blocking the HSAB's will block the air from the metering block....and give you more gas up high. open up the HSAB's and you'll lean out, up high.
...as for the lsab's...
I hear it's the opposite. Open them up...and you'll lean out at idle. Close them for more gas at idle.
After many hours and tons of drilling air bleeds with a custom drill bit kit i bought (#1 bit to #60 bit)...i've concluded that it isn't worth the effort
This all applies to my own setup, of course.
I changed the primary lsab one drill size larger with success. It leaned out my idle air fuel about .3 and seems to start easier. I think the manners are slightly worse, though
I have a holley HP main body, lsab's were 75 I believe, stock. I went one size larger (the drill bit that fit....a #48 I believe...probably a size 78 air bleed or so)
I tried one size larger drill bit than that...and dropped .5 or .6 air fuel but lost a lot of street manners. Car surged and was quite nasty
I tried changing the secondary LSAB's and even one drill size difference made a similar effect - murdered the idle. Felt like I had a huge cam in the engine..loping and having issues
I'm going to do a bit more testing to see if I like the stock LSAb on the primary...or one change larger...but it isn't a big deal either way as we're talking a .2 or .3 difference...
I think i'm going to end up with the stock air bleeds.
For the hell of it, I tried changing the LSAb's radically (3 or 4 bit sizes...10 or 15 # sizes, I imagine)
The car would barely start
So, just as you read....low speed air bleeds are touchy and only for FINE tuning. Probably not worth your effort, in my opinion
That doesn't mean that you might not have a problem with lsab's....maybe yours need changed. But it appears the 'stock' ones were the 'right' ones for me
High speed air bleeds, on the other hand....highly recommended to block