Ive learned that the 5.7, 10,000 GVW ,4 bolt main engine in my 92 Vandura 14ft box van has been discontinued....i put her on the scales yesterday and she's 9,500lbs now that I've converted her into an RV!! Summit Racing says they make a 2 bolt main 7,500 gvw and under 5.7 but I'm worried its not gonna have enough power....Any ideas?

 

Can you bump up to a big block?