When we (EBM and myself) began modifying my motor, we kept putting smaller and smaller pulleys on the Merc/Weiand 256 to keep the boost up with better flowing heads and bigger cam, etc. It comes with a 4" pulley and they seem to hold up about 150hrs. turned slowly. I put the AZSM kit (with a 3.5") on the motor right after I bought it. The additional boost (4 to 6 PSI) did help the stock low compression set up. With the additions of Dart Pro 1s and a hydraulic roller, I went to a 3" pulley to keep the boost up around 6PSI. Unfortunately the 256was about 12,000 RPM at WOT and was going through bearings and seals like sheet through a goose. The 871 solved all that. I am running 8PSI at 10% over (estimated 6,600 blower RPM), and it has held up very well. The only thing I've done to it after 3 years was have it restripped, timed and new bearings and seals. It never used a drop of oil. I am using Red Line Shockproof. I am not running an intercooler. The bigger blower with helix rotors is much more efficient than the the 256. I did run a Whipple IC with that (W256) blower, and it did help. The Whipple IC for the 256 needs a new top plate to fit a 71 series blower. The blower discharge outlet is much larger.
Your tuner may have to do some remapping and/or change the fuel pressure to keep up with the bigger blower.
EBM here has several 575 maps if you need your done.
Happy Holidays everyone.
Steve

BTW, I should have mentioned that the W256 with the Whipple standard (not MOAC) intercooler is the exact same vertical height as the BS 871 and BS aluminum intake manifold. Both are 1 7/8"s taller than the stock setup. As for the performance difference on my boat, the 871 has a lot more torque and acelleration at any speed. Of course your drive(s) may not like that :grinser010:......
Biggus, you could sell your 256s and Whipple ICs, and install the 871s. That's what I did.
Regards,
Steve

Thanks for the info Steve, you've got me thinking...:drink:

I'd like to retain the Whipple intercooler and possibly go with the 871 if it's only 1.78" taller, I could modify the underside of the hatch again without it altering the outside too much. (as you can see in the pic, we had to make inserts when the intercoolers were installed) I do not want scoops.

Greatly appreciate the info!

Kurt

Not sure the whipple 256 cooler will work with the standard 671/871 pattern. I am running an 871 littlefield with whipple low pro cooler.

The BS 250 is a lot beefier than the wieand...offload the blue 250/6s while they are still in one piece (and worth a premium). Its not pretty when they grenade, rotors bend, bearing support plates break. About the only thing salvageable is the case.

That's the plan. Mine were rebuilt by TBS, little hrs. Any guess what they would be worth? Ebay?

Any idea on pricing for the top plate to adapt my Whipple 256 intercooler to the 71 series blower? -tried to look up on Whipple's site, must be down...

Coolerman, is this something I could get from you?

Thanks,

Kurt

Thanks for asking Kurt, but we don't have anything for the 575's.

Coolerman,
Those are some great looking intercoolers you have there.
What are they doing on the dyno?
Best Regards,
Steve

Kurt, it may be possible to machine your Whipple IC top plates to fit the 871 outlet. If you have a good machine shop nearby you could run it by them. Get a 871 gasket and lay it out on top of the intercooler. That's your 871 pattern. There will be some new mounting hardware required too. I looked at doing the same, but going with the 871 and BS intake without the IC allowed me to keep current hatch setup. Like you, I had already modified it once to clear the W256 with IC.
No doubt the BS 871 and Whipple IC together would be a great setup...........
Regards,
Steve