I plan on rebuilding my 300 for more power(of course). Can I use a 240 head for a higher compression ratio? If so would I benefit from larger valves or will the stockers work? I would like to keep as much of my low end as possible.

 

Yes, the 240 head can be used without larger valves -- I believe stock valves were the same on both. Acc. to Clifford and from what I have seen over at fordsix, larger valves (usually chevy SB) are helpful but if you go too large, you will destroy the torque. For racing, the guys were with very strange cam and valve combos that would not be fun to drive on the road at all. The 300 can be made to live in the 6000 to 7000 RPM range this way. I recently bumped into a old dirt track racer here (western Kansas) that recalls putting together many a 6 for dirt track racing -- at 7000 rpm, they sound pretty wild, and coming out of the curve they have better initial pickup and torque over the 8, but then the 8s eventually would catch up by the next curve. Or so he said.

Shaving a 300 head gets you the same effect, or flat pistons or or or -- the best place to ask this question is over at fordsix -- I am just paroting what I have read there.

FYI -- there seems to be a place on ebay that sells remaned 240 heads quite frequently for around $200 -- wish I have know that before I sank $450 into my 240 to have hard valve seats and guides put in so that I could burn unleaded. The same dealer on eBay sells 300 heads for about $100 more. Maybe supply and demand? 240's get junked pretty frequently, and maybe they get the heads for free more or less. Who knows, FYI nonetheless.

 

Thanks cdherman for your reply it was quite helpful. Will intakes and exh. manifolds designed for the 300 bolt up to a 240 head w/o modification?


only little boys wear bowties:x25

 

Yes, manifolds, and just about everything else, is identical in 240 and 300. Differences are: crank, rods, pistons, head chamber

Some otherstuff was occassionally different, but more due to year to year variants -- harmonic damper is more often 3 ring on 300. But the same damper will bolt up to a 240.

EFI cast exhaust manifolds from 87-96 are bolt up too, though I think some guys report needing to grind a little in one location to get them to clear stock intake. But if you are going performance, you want an aftermarket intake regardless. I can't decide what I want to do -- so I am bone stock now, but will likely decide at some point and build up an engine with the old one still in the truck, so as to minimize down time.

later....