Hi. Posted here quite a while ago. Time for more ideas. I like reading some of the great, informative posts here. It's been educational.
Ok..to help explain my cryptic subject line, I own a 79 class C motorhome built on a Chevrolet G30 van chassis. It has a 400 CID engine that runs very well. It has good enough power to propel the 5 ton vehicle on level ground quite nicely. It can easily keep up with all traffic..until I have to go uphill and, let me tell you, here in Alberta we have some nice hills. ;-)
It really runs out of breath to the point that I have my foot to the floor trying to keep it barely traveling at 70-80 kilometers per hour [about 35-50 miles per hour]. It could never make a trip to British Columbia, which is ironic since it was built in British Columbia. It burns no oil and compression is 140 at the lowest and 150 at the highest. I have rebuilt the carb and did all the standard tune-up stuff. [filters, plugs, wires, cap, rotor, coil...] I am happy with how well it runs, it just needs more grunt. I have verified that the secondaries are indeed opening.
It has been suggested by a few engine builders I have met that I might have great luck with an Edelbrock Performer Plus camshaft and a Performer or Performer Air-Gap manifold. I have decided against headers as the excessive heat may be too much under the doghouse. It's already rather warm for my front seat passenger. Not to mention my XYL's objections to the throaty sound that we all love. *sigh*
In the past I have considered engine swaps with a 454 or a Cadillac
500. Both would probably be great but I really don't need the extra work or expense.The graphs at Jegs show a rather surprising jump in torque from 2500 to 3500 rpm which is right about where you need it most on the highway with a motorhome.
I am interested in a few opinions and perhaps a little discussion. I would not be opposed to more intense engine massaging during the off-season, depending on opinions regarding any potential benefits that any mods would provide.
I am really interested in your opinions.