Just bought a weiand action plus instake off eBay and am thinking of doing a cam swap at the same time. I currently have a stock 400sbc with the exception of headers. I have heard alot of good about those comp 4x4 extreme cams. Looking in Summit racing catalog and not sure which size to order. I'm looking for good off-idle power and such for 4x4ing. Any pointers on which to get? Thanks!