Update on solas pumps:
As mentioned above, different impellers will require different amounts of spacing to install properly. We have been using oem prop spacers (2mm) for some and custom ordered 3mm spacers for others.
The biggest installation issue that has been found so far:
http://www.x-h2o.com/threads/110333-I-give-up-Solas-pump-help-PLEASE
The issue is with the spacing of the bearing hub relative to the pump body. The solas pump has the center hub a little forward (about 5mm as measured by carl at cold fusion) as compared to the oem pump stator.
This makes the same oem driveshaft effectively longer when mounted in the solas pump. It doesnt seem to be an issue in oem hulls since the spline underlap is large enough to accomodate the difference, but many/most a/m hulls seem to be designed to increase spline overlap as compared to oem hulls so many guys have had issues installing in solas pumps in a/m hulls.
You can often fix the issue with a combination of moving midshaft housing forward with a Cold Fusion spacer, removing thrust washer behind coupler, and moving midshaft farther forward relative the housing. We are also building custom length shorter driveshafts for solas pumps to fix this issue altogether.
In spite of this issue, the feedback has been overwhelmingly positive on the quality and performance of these cost effective pumps.