Welcome to the forum. I don't have the answers for your questions.
But, when you say it doesn't have the power to handle the mountains, will it not make it up the mountain? Or is it just slow because it's underpowered?
A lot of RV's go slow up mountains.
Is your 318 tuned and running properly?
Would it be more cost effective to do some modifications to the 318, headers, etc., to get a little more power?
RVing isn't a race. My 96 Southwind, 454, is no ball of fire going up mountains but, it always gets us where we're going.
Good luck with whatever you decide. Keep us updated.
Please, post a picture of your Camperwagon when you get a chance.
