It depends on which 327 it is and which 350 it is. A mid 70's 350 in stock form is a dog (155hp in RPO LM1 form), but a earlier engine is not. 327's could be had in 2bbl form in cars like the Biscayne and as the base V8 in 67-68 Camaros ( replaced by the hideous 307 in 69 , IIRC). 327's could also be had as the highest HP factory rated Gen 1 Small Block in the 1964 Fuelie Vette with 375 hp, and the 350 could be had in 360-370 hp LT-1 form in 1970. Even pedestrian 4bbl 350's from 1967-1970 had 10.25:1 compression in RPO L-48 form in Novas and Camaros. So, it really all boils down to what you have in front of you and what you plan to do with it once you get it. Oh, one other thing: in the late 60's/early 70's Chevy switched it's accessory drives and how they were mounted. Early heads do not have the bolt hole provisions on the ends for use with the later brackets. The early brackets used the exhaust manifold for the alternator bracket and the later ones are all bolted to the heads using the 3 drilled and tapped holes on the ends. The last vehicles with the old style brackets from the factory were the 1972 Chevy and GMC pickups, but everything else phased in the new brackets over the previous several years.