Interesting... I recently encountered a similar out-of-flat-level with my SB... using the Schumacher poly-mounts. It appeared to be small... maybe only 2-3-4 degrees out-of-level. The steering linkage (idler arm) was slightly rubbing against the headers. Those mounts MAY have to be massaged to fit the dowel-pin into the factory k-frame... I did that... and you can compare the dowel pins... they are NOT the same (Schumacher vs OE rubber type). However, I still had to loosen ALL the bolts... motor mount bolts, exhaust/header bolts at the collector, trans mount, lower and upper radiator hoses... everywhere! Then, re-settle the engine back down into the k-frame.. flat as I could see ... and re-tighten ALL the bolts.

Actually, I think the Schumacher mounts aren't as TALL as the factory typical rubber mounts.... thus... lowering the engine slightly which welcomes interference with the headers and steering linkage... in particular.. my longer C-Body IDLER ARM (aka: Fast Ratio).. no problem with the factory FAST RATIO PITMAN ARM. Granted, most of us are not running this setup as I am, but... it was a surprise to me when using the Schumacher poly mounts.

BUT, I will say, the rubber mounts have a huge amount of twist and flex... incredible amount!!!... just put one into a vise and twist and see... unbelievable amount of twist!

The Schumacher mounts do NOT give any additional noticeable vibration... which is good.... nothing to be concerned about.

There's no problem installing a BB into a V8 E-body k-frame... just use the correct common motor mounts.

Hope this is helpful.

Mopar Mitch "Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers! Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!