I had a '93 Chevy van w/350 like your talking about. I tried pulling my 7K Grady-White. It did "OK" on level ground but absolutely died on long hills. On a 5% grade it would hit 4500+ RPM just to maintain 45MPH. When you work a smallblock that hard for a long period, It's going to take it's toll on the engine. 330Ft of tourque isn't much when your towing. As for rear-end ratio -- I would look for 3:73 -- 4:10 if your going to go with a smaller enegine. As stated --- It's NOT going to impress you when you hit the hills.
