One thing you have to remember, if your vehicle was built after 72, the horsepower rating is differential rather than flywheel. That means that your eninge is actually putting out about 185-195 HP at the flywheel, and I am sure if you check the specs and compare, you will find it is putting out abit more torque then a standard 302/5.0 of the same time period. BTW, back in the late 60's and early 70's, in pickups, the 300 Was rated at 170 HP at the flywheel, and this was with 7.9:1 compression.
, is the website to go to for finding goodies for your 300 I-6.
They are very susceptable to even the most minor of modifications.
They are a very sturdy engine and will last quite long with good regular maintainance.
With a 4 inch bore and 3.98 inch stroke,veing a nearly square engine, dont expect to be able to turn them the kind of RPM you would expect out of a V-8 of similar state of tune and displacement. But then you dont have to.
Rule of thumb. Given a 6 and an 8 of similar displacement and state of Tune, the 6 will produce 30-40% more torque than will the 8 cylinder.
Torque is the real game, not horsepower, as horsepower is mearly a mathmatical formula to convert Torque to something people can relate to.
Knowing the year and type of induction system you have currently would help a lot. That being said, if its a carbureted version, an aftermarket intake, with a 390-450 CFM, vacuum secondary 4 bbl, and a set of headers with high capacity exhaust, would do wonders for your 300. Clifford makes intakes, cams, and headers, as well as some more exotic parts for your 300, and Offenhauser makes a couple different manifolds.
Recurving of your distributor is also an essential to getting the most out of your engine.