Modifying a 1975 460, I want torque! going into an 86 f250.

SO which cam would do the job?
I know to switch the gears back to 1969.

No i don't have a lot of cash so i don't need the best, good is ok.

Headers, intake manifold? are these cost effective mods? if so recomendations please.

thanks, also i heard the the exhaust manifolds like to crack, as well as the heads in this engine? true/false?

greg

 

Here goes: You're hurting most in the compression department, compression is directly responsible for torque so that should be number one priority, although not a cheap fix. You can get a set of '70 or older heads with the small ~72cc combustion chambers, or you can go with another piston to boost compression with the current heads. Your intake is fine, saw a shootout where the only intake that clearly beat the stocker for TORQUE was an Edelbrock Performer, horsepower is a different story. I'd put a mild cam in it as well, something around .500 lift and under 210 degrees duration. I've seen quite a few cracked exhaust manifolds but never a cracked head, and to my knowledge it's not a problem. Hope this helps.

 

Recurve distributor for quicker advance. Possibly use crane cam distributor recurve/vacuum advance replacement kit for do it yourself recurve with instructions in it. If you don't port and polish heads just use truck/rv flowmasters/2.5 inch duals with stock manifolds. Also install cooler thermostat (180 degree) instead of 192 one, Factory TSB suggestion for better idle, along with Red Line brand water wetter coolant additive. K&N air filter taller than stock (to raise air cleaner top up off of base) and K&N stub stack plastic velocity stack if you have Holley carb, with rochester, no stack available. Use cam with increased exhaust duration/lift over stock to compensate for restricted exhaust port. (Maybe Crane RV type?)If you port heads then use headers. PAW catalog has most of the aftermarket stuff. They even sell a 521" stroker/bore kit if you really get serious about towing power. Did all of this except the stroker to a stock block and wound up in the 300hp range without cam/compression change.

 

hey Greg, how are ya. to tell ya the truth the only way for torque is to bore. this is what i use then you judge for your self... '73 block .060 over, 19cc. or 22cc. dished pistons i for get which ones, moly rings, melling high volume oil pump, heads are 1972 open chamber porting by my self on the exhaust side, stock rocker arms, crane valve springs-single sping with dampner, edelbrock dual plane intake with a 2' carb spacer in between, and 750 double pumper, with headers from l&l headers they guarentee 40 h.p. just bolting these on. now this motor currently has 105,000 miles on it and still runs fantastic all the pulling power you could probally want about a very conservative 425 h.p. about once a month i'll run 10 gals. of 110 octane and 10gals of 93 octane mixed for a wild ride all this is in a 77 f-150 4 wheel drive. with a 3:50 ratio rear this runs great and you still get good highway running out of it.oh the cam is a crane grind part number #353942 almost forgot and a stock distributor. no alot of money to build but it runs awsome. well just one way to go. Ray ....

 

I wouldn't say 425 was conservative. It might be a little liberal. I think you'd be around 400 hp, max, at the flywheel, but with near 500 ft.lbs. of torque out to almost 4000 rpms. It is a heck of an engine. I am currently building one very similar.

 

I'd say 425hp is right on the money. I've referred to this a million times but Super Ford did a buildup of that engine, with the same exact 393492 cam, edelbrock performer, and lightly ported stock heasds. Made 430 hp at 5000rpm and 530 ft-lbs at 3900rpm. Great truck motor. If you're using a performer RPM you'll have a little more HP and a little less torque.

 

Chilly,
Yeah, but they had a lot more compression than this guy is going to have. He is probably running around 8.5:1 from what he stated. They also used D0VE-C heads. This guy is using open chambered heads. I don't think he's quite up to 425. Like I said about 400.

 

I agree. The motor they had ran with 9.4:1 compression so it wasn't a ton of compression, but definitely noticeable, 400hp would be a good conservative guess. Interesting thing, I've only seen one dyno test of compression changes, I know it's a bitch to test something like that but it would be nice to know. In that test, they got roughly 12hp for each full point of compression. Remember, you have to decrease timing with more compression so the "net" gain of more compression isn't as great as would be expected. I know these dyno tests aren't always accurate, just passing it on.

 

what's up ford lovers? just to let you know when we put this motor together it was figured out at 9.6:1 comp. with the D2VE-A2A heads still have the card we wrote things down on it, now realize i'm using l&l headers on this engine that's 40 h.p. just bolting these on, if you don't beleive this call l&l and ask them, that's what these folks told me, and it was like going from a 2 bbl. carb to a 4bbl. carb when these were put on, a MAJOR, increase!very noticable and well worth the money.. the one thing i can't remember is if we decked the block or did we cut the heads a little.we did one or the other. i know my figures are very close. running about 12 degrees of initial timing, don't know right off what the total timing is. you all have a great weekend.

 

For starts, boring isn't always the answer to torque. It helps, but the real answer is to stroke it. The shorter the stroke, the faster the engine turns. Speed doesn't built torque. You want a long stroke. Might I recomend a Comp Xtreme 4x4 Cam. I have one in my freshly built 460 and I am impressed with it. It builds off idle torque and doesn't sacrifice vacuum. L&L headers is also a good choice. I would try to stay away from high compression ratios. They help but if you go too high you can't run unleaded fuel with out having detonation. I recomend about 9 to 1.