Hi all, im starting to plan a rebuild on my truck. 86 ford f250, 460 4x4 with a 4spd hopefully going to 5spd after the motor. All ideas are welcome but im stuck on shorty headers or staying with stock exhaust. Im going for a towing truck but i also daily it so im doing small upgrades for hp too. So hers what i have down so far. Long block with flat head pistons, mild r.v. cam, edelbrock performence duel plane intake manifold, edelbrock 750cfm carb. D0VE heads are real hard to find in my part of oregon and get overpriced so thats why those arent on the list as well. I am also probably going with a Y into single 3in exhaust dumped before the alxe unless it makes more sense to do duel 2.5in. Thanks in advance for the help!

 

Stock manifolds are, in general, more durable and provide more low-end power. Headers don't do much on these engines as the heads are so restrictive.

 

ok thank you, ill just either get stock replacements or get mine fluxed and decked.

 

Noticed you said you're planning the rebuild. Have you completely ruled out head modifications? Allowing the exhaust to breath better will give you the boost you are looking for. A higher lift short-duration cam will give you good RV power band as well. I run headers on all my vehicles except my little Explorer, I'd definiftely go with the 2.5 dual exhaust with a cross-over pipe or a X-type exhaust. The idea being to give you RV range for your ponies, at least moving your back pressure further downstream. ALso, with a head change you can play with your compression ratio. I'd suggest no more than 10:1 unless you decide on aluminum heads. This will give you a nice boost as well and still let you use pump gas with no problems. I'd suggest you try some Ebay auctions, you can pick up some heads for a reasonable price there. I know what you mean about DOVE heads, but honestly putting those on an 86 engine with flat top pistons could give you a compression ratio that is unworkable for pump gas. Check you combustion chamber volume, I think '86's ran about 85-90-something cc;s, DOVE's are 75cc's. I hope this gives you some ideas, and I'm sure you will be able to build something you're happy with given the right combination. Good luck,FTE'er!

 

The rebuild is out of necesity since i eat about a quart of oil every 200 miles or so, 8th cylinder is shot. Ive been working with s&j engines on getting a reman with flat top pistions with valve releafs as well as an rv cam. Got told the pistions will work with aluminum heads when i have the money to go to them, then for sure getting headers just kind of dont want long tubes due to fitment issues but ill get to it when that road hits. Thank you for the advice on the exhuast ive been stuck on that one lately

 

A good build for truck would be the early EFI pistons with the really shallow dish almost flattops,zero deck the block as necessary to get good quench distance since most common head gaskets seem to be around .045",use the EFI timing set which sets the cam with no retard.Your big chamber heads will give somewhere between 9.5 and 10.0 with this setup which will tolerate pump gas if you get the quench distance right.I'm with Mitch on the exhaust porting the gains are well worth the effort expended,even with stock valve sizes.With a heavy 4x4 and a mild cam avoid the temptation to get the performer rpm and go with the regular performer intake.If you insist on manifolds make sure to use the largest outlet truck manfolds or PI's if you can find some and if they fit.I also like the super single exhaust but if you can you might want larger than 3" a good fit for these trucks is the OBS powerstroke tail pipe which is a 3.5 " mild stainless pipe they are typically still in good shape in wrecking yards if they haven't been bent up in a crash or by the forkloader.Lastly make sure what ever distributor you use has a performance curve in it,stockers or chainstore rebuilds can be lazy.I prefer the Duraspark with a curve kit in it.The Ford distributor is a quality piece with lots of adjustability including the vacuum advance.The modules evolved into a reliable box after the first few years of production.Some people poo poo the edelbrock carb and while it may not quite have the potential of a holley I've had good luck with them when properly calibrated they run good and give as good a fuel mileage as can be expected,with the listed modifications for the engine the 750 will most likely need deviation from the factory supplied calibration especially if you decide to port the heads in the exhaust ports.

 

so to start, im getting a rebuilt engine with slight mods done to it which makes porting and all that not likely to be done. The upgrades include "rv cam", flat top pistons with valve reliefs which i was told would work with upgraded alum. heads if i wanted down the road. Headers were to just help with out flow as minimal of a gain as it might be. I will be going with a 750 edelbrock since it is 4x4 and have heard of fuel issues on some larger inclines, and my father knows a bit when it comes to tuning. The rest is going to be close to stock but not quite. This truck is still a daily but might also be pulling larger 5th wheel some times. I also got a great deal on a zf5 so thats getting rebuilt and put in as well

 

I'm putting a rebuilt 460 from a mid-80's F-250 into my 78 Bronco and for simplicity I'm just using the factory exhaust manifolds. I'll probably swap in some headers later on when I find a set that fits the way I'd like and are affordable. This 460 will be built very similarly to another 460 I had and that previous one made about 425hp at the flywheel on the dyno. It had headers, so I'd expect this 460 going into my Bronco to make a little less power due to that. Here's a couple pics of the manifolds, I had them blasted and high-temp powder coated.

 

Those look like the big outlet truck manifolds they should be around 2.5" outlet much better than the non PI car manifolds.

 

Just a few more thoughts. You might want to think about a weiand 8012 dual plane intake, rather than the Edelbrock. The Weiand flows better. It's a 4150 pattern for the Carb, which should suit your Edelbrock Carb, I believe(I've never used one, so not sure of the pattern). As for the exhaust(again), as you can see from the pics posted by Doosenberry, all the exhaust of each bank dumps VERY quickly into the stock pipe collector. This "jams-up" the air and causes the back pressure i mentioned earlier. A good set of shorty headers moves it further downstream, though not much, and usually have larger outlets to mate to the pipe. These engines were good breathers for their time, but their achilles heel has still been their exhaust. Reducing back pressure or moving it as far downstream, since you're not porting yet, is the only way I know to help it out. Otherwise it's like a pro runner with asthma.LOL

 

haha yeah that makes sense, i would look into the weiand but i already have a edelbrock dual plane proformer intake in my garage. I got to the point after a week that i will just have to learn tig welding and make my own a little while down the road

 

Actually given his application of 3/4 ton 4x4 and the weight that goes with it,the performer is a better choice,while the stealth works great for light,high rpm applications due to the higher flow capabilities,the large internal volume of the intake can make for soft throttle response in heavy low rpm applications and make for less than enjoyable street manners.The same applies to a lesser extent to the performer rpm.

 

Wassup,while going with a standard rebuilder engine is quick and easy it is also easy to wind up with an engine that your not very happy with.It can wind up with a relatively low compression ratio and still not be terribly happy with pump gas.Rebuilder pistons have a lower compression height to accommodate any block decking that maybe necessary but most blocks require little or no decking that winds up with the piston down in the hole an excessive amount.If your builder is willing to check the distance and deck the block as necessary to get it right your good to go.Between the deck clearance and head gasket thickness if your more than .055-.060 your losing efficiency and pump gas tolerance.You may want to talk to your builder to see if they address these areas if they do you should be good to go,if not you may want to ask if they offer that as an extra cost option.

 

yeah ive been in talks with them, and they are doing some little things on top of being a standard block like different piston heads and upgraded cam, i should be getting a full build sheet with it as well