ratty......though the GMC V-6 makes an excellent truck engine the weight and low RPM's of these engines doesn't make it a very good power plant for a rod...Their bellhousing will accept most any GM standard tranny and there were adapters for the two speed powerglide...The 305E and 351M for examples are probably some of the most reliable engines ever made..200,000 miles of hard use is not uncommon.....