A lot of engines end up with the "It'll make a good boat anchor" tag but that is not at all a true statement when it comes to the GMC V/6...they do not make good boat anchors. Those ****ers are so heavy they would pull any boat immediately to the bottom.
I have a 351E "big block v6" in my 67 GMC as well, there is a lot of good info out there on them. They aren't one of the most efficient motors out there, and there aren't a lot of parts available, some of the guys on the http://www.6066gmcguy.org site has some performance Ideas for them, and a few good tips, but there isn't much that you can do to turn them up. GMC made three flavors of the 351 6, the 351, the 351M and the 351E, the latter two were called "Magnums" the standard 351 rated 189HP @ 3400 rpm, and 312ft/lbs @ 1800-2000. The 351M rated 220HP @ 4000 rpm, and 320ft/lbs @ 1600 rpm, and the 351E rated 220HP @ 4000 rpm, and 320ft/lbs @ 1600 rpm. They all came with 2 barrel carbs, but the manifolds can be altered to accept a 4 bbl if you want a little more fuel. The Magnum motors had larger port heads and bigger manifolds. They really didn't rap much higher than about 5000 rpm, but if you didn't firewall them they ran strong for a lifetime. I kinda dig the old motors, but then I like the AMC gremlin, so take my opinion with a grain of salt! Like I said there is a lot of good advice on the 6066 site about these motors, and if you decide you don't want it there are a lot of guys on there that would jump at the chance for it. Hope I helped some!
The Jalopy Journal
