The 305's and 307's are both downsized versions of bigger engines. The 307 had a 283 bore, with a 327 stroke, trying to gain the advantage of the long stroke crankshaft without the gas-hogging cubic inches of the 327. fast-forward a few years, and match up a 265 bore with a 350 stroke, and call it a 305! Same concept, long-stroke torque, and fewer cubes to feed. As long as the gear ratio is right, the 305 will pull a lot of load, just don't expect it to happen quickly. Make sure the rebuild included a new camshaft, and also be sure the EGR valve has the correct volume restrictor bushing in the stem. The reason for 305 camshafts failing was an overheating condition around the #4 cylinder pushrods caused by too much heat through the EGR passage. It caused oil to coke, and build up around the pushrods. The resulting load on the cam lobes caused flattening of the lobe, usually on the #4 exhaust valve. If it wasn't done already, installing flattop pistons in the 305 will make it a pretty respectable load-pulling engine, along with a Comp Cams RV camshaft.
Jerry

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