The V8 Owners Forum -

If the blower came off a 3.5 and is now on a bigger capacity engine I would think that it is " starving" the engine due to being set-up for a smaller volumetric flow, hence the vacuum reading. The only fix could be going higher on the overdrive pulley to deliver more air but that will drop your redl...

Don't forget once you have resized them to weigh each rod and compare the weights of each. You may need to trim one or more to get the weights close together again.
If you can afford it have them shot peened before fitting to relieve any stresses that may have occurred.

I swapped my BW35 for the LT77 and used the auto bellhousing with an adapter plate and some machining to fit the release arm out the side and a mount for the slave. Propshaft was the original auto. Some fiddling with the rear mount, but not serious. I took my pedal box/mount out and custom fitted th...