Ihave an inline 6 in my 86 f250 4x4.   I would like to find out what others have done to bring out a few extra horse power and torque.

Headers ? carb? bored out, looks like lots of block for that.  Deck the head?

I dont need a ton of extra power but a few extra ponies would be nice.

Thanks , John

No persoonal experience, but I have a friend that put headers and exhaust on his and noticed a differnece, really woke up the tired engine.  

go with carb and headers for a simple upgrade add camshaft ignition and tranny regear for more extensive upgrade. i have a friend who just hauled over 12000# on the bed of a flatbed 350 with the straight six and thats all he has done to it  

jhasty4:
go with carb and headers for a simple upgrade add camshaft ignition and tranny regear for more extensive upgrade. i have a friend who just hauled over 12000# on the bed of a flatbed 350 with the straight six and thats all he has done to it

I would skip the headers because they will take away form low end torque that 300's are famous for. A carb and a mild cam upgrade together with some deeper axle gears would make a big difference. With proper gearing, 6's can move a lot of weight. In the 70's I hauled a fullsized car on a trailer for Ohio to Tenn near NC border with a 66 Chevy P/U with a 250 in it. It came stock with 4.57 gear and did a fine job pulling it even on interstate hills. Back before there was emissions, 6's did a fine job. In later 70's I new a a old retired guy that had a stock 58 C60 chevy single axle dump truck that was cherry. He had gotten it out of a farm sale and hired out for $40/hr to haul gravel and asphalt on big construction jobs when contractors were hiring every truck they could find. His normal load was 8 tons and it hauled it fine without breaking a sweat His total GVW with that load was around 28 to 30K.  BTW, it had a 261 six with 4 speed and a two speed rear axle. He said it got about 8 to 10 MPG average too working too. Sad part is I could have bought that truck for 900 bucks back then. I wish I had and parked it in barn as it would be neat to have today and in full working order.  

clifford racing has a lot of 300 six parts aftermarket stuff. He cuts cams and other related coolstuff. headers are a great upgread but pipe dia. is critical for low end 1 5/8 is a good start for 300 six on low end torque and midrange. On the engine 0 deck and make compression and goodcam. headers help with detonation prevention. Gets heat away from engine better than factory manifold. good aluminum intake and about 600cfm carb for starters.  

wyomingtrailheader:
clifford racing has a lot of 300 six parts aftermarket stuff. He cuts cams and other related coolstuff. headers are a great upgread but pipe dia. is critical for low end 1 5/8 is a good start for 300 six on low end torque and midrange. On the engine 0 deck and make compression and goodcam. headers help with detonation prevention. Gets heat away from engine better than factory manifold. good aluminum intake and about 600cfm carb for starters.

Any header is going to take away for low RPM torque. You cannot let cylinder pressure blow down too quick if you want best possible torque at low RPM's. Also a 600CFM is WAY too big for a 300. Try maybe a 450. Carbs are not like super chargers or bigger is better. Too big and air velocity through them is too low and performance suffers.  

once built a 300 six with clifford headers solid cam and a 600cfm 1 to 1 linkage holley. That little dude ran good. Some head work on porting was done but it still didn't give me the low end torque that I wanted. Later did a 400 ford with some upgrade and out performed my little 300 six I have built many ford engines for 4wds and still building. On the low end torque and headers hurting torque, you must have ran to big a tube and collector. its all about cam profiles and how they are cut for low end torque. On the cfm's for a engine big question and lots of possibilites. I currently run a 472 ford with 950 cfm 1 to 1 linkage set up and fully tunable air bleeds and metering plates. I do keep my exhaust pipe dia down for low end torque for 4wd's and run certain mufflers per application. On the cylinder blowing down that is done with camshaft timing on exhaust opening. I had a cam cut purposely for low and mid range for a 460 in a heavy truck and all my performance buddies didn't understand but I love that cam and still currently running it. Proper torque converter built also. I need more info why yours hurt torque.  

On headers their are many out their and for 4wd trucks I like long tube headers and tri Y's. clifford makes a good header for 300 six. one of the potential problems with a factory manifold is hot spots. Plus anything you can do to get heat off the exhaust valve helps detonation prevention. I havent done a 300 six in a long time but clifford is still out their making it work for his guy's. My first 300 six started with a comp cam 268hyd and thats a good start for a guy learning a engine in 4wd world. Hope this helped out on info for bc logger. its nice to have different point of views on subjects and able to learn on what you really want. by the way I spent about $5000 on 300six to run its best. Lots of good machine work and nice parts and head work.