I am installing the B@M EFI blower as we speak. Holley says I need the 155195 pulley (4.10 diameter I think) which the Holley guide says makes 4-5lbs. The guy who originally had the blower ran it on a 454 mag like mine and said it made 5-6lbs. with the 155193 pulley (3.65 diameter I think) and he ran it around 5400 rpm. The Holley guide says this 155193 pulley makes 8-9lbs. But doesn't list any RPM's. Does anybody out there know what pulley makes what on the 454 with the B@M 250 and at what RPM. I have both of the pulley's listed and will get the one in between if I need to but I want to know which one is most likely it. I have heard that Holleys listings are out to lunch but I don't really know. Thanks.

PS. I am going to dinner soon so I apologize for not checking this post for a little while but will check when i get back.

#155191 (502c.i.) = 8-9lbs boost
#155192 (502c.i.) = 6-7lbs boost
#155193 (502c.i.) = 4-5lbs boost ; (454c.i.) = 8-9lbs boost
#155194 (454c.i.) = 6-7lbs boost
#155195 (454c.i.) = 4-5lbs boost

These figures are rough to say the least.

Any raising or lowering of compression ratio (via pistons , boring or heads) will have adverse affect on boost. Increasing c.i. or lowering comp. ratio will net less boost. Increasing comp. ratio will net more boost.

Boost is a funny thing. You will not always see highest boost at highest rpm. Load on motor is a big determining factor.

I run a 250SC with the #155193 on a 461(454 .030 over). I see 6-7lbs of boost.

Good Luck

I'm running the 3's on a stock 502 8.75:1 compression and I see the 4-5 lbs that hotbeek mentions at 5300. A boost gauge is the only real way to tell.

I think I'm gonna start with the 195 pulley and see what boost I am making. It just confuses me that it was making 5-6lbs. with the 193 pulley for the original owner. Maybe it was because it was on the Dyno and the load on the water will be significantly different. We'll see! Thanks guys. I'm going to post pics and speeds when it gets finished (hopefully testing next Friday afternoon).

Condition of blower rotors will also affect boost.

The sooner the pics and info. get here the better!

Have fun !

I have the same blower system as you and had to go up to the 8-9# pulley to make 5# boost on the gauge but I do boat at 5-6000FT elev.post your results here as I don't know to many guys running the b&m 250efi and wouln like to compare notes.