Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

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Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

November 11, 2013, 10:59:32 PM

I have another 255 question. Will the exhaust manifolds that are on my 255 v8 fit my 351w? If so, will they clear the column shift linkage?

I am aware they probably don't flow great, but as long as they flow well enough for a stock 351w, it would save me some money, heh.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #1 – November 12, 2013, 12:30:10 AM

the 255 has the same deck height as a 302 as far as I know. it is just a debored 302 block. the 351w is a wider 9.5" (as opposed to the 302 sized 8.2"), so the block is physically wider. 302 manifolds should fit, but they will be angled differently due to the wider shape. you might be able to get your exhaust to work with a bit of tweaking, but I'm not sure.

no idea on the shifted linkages.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #2 – November 12, 2013, 05:30:23 PM

A 351w is one inch taller and 1 inch wider than a 302 (255,260,289). Chances are the logs will bolt up but the column shift linkage will be in the way. The exhaust will end up being a fab job for the down pipes.

I have seen a 351w in a fairmont with column shift linkage. The guy used spacers to life the engine higher at the mounts. It required a cowl hood but it did work.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #3 – November 12, 2013, 06:38:22 PM

Thanks guys.

Yeah, I don't much care if I can't reuse the current exhaust pipes, I'd like to go duals anyway. I just would rather not shell out $200ish for special swap headers if I can get away with using the old manifolds.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #4 – November 12, 2013, 07:58:33 PM

you could probably sell the 255 crank to someone wanting to build a high RPM screamer 302. they are the same specs, only lighter... some say 10 pounds lighter...

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #5 – November 12, 2013, 09:58:29 PM

they are forged and hollowed out. supposedly good for 600hp. I've seen claims between 22-28#'s.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #6 – November 12, 2013, 10:45:13 PM

Too bad the rest of the motor isn't good for 600hp, lol.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #7 – November 13, 2013, 12:57:00 AM

The 255 cranks is no more than 5 to 6 pounds lighter.

Using a 255 crank in a 600 horse engine is laughable at best. With any kind of power adder, it won't last long. We all know that stock blocks are none too long-lived anyway. Put a belt drive supercharger on there and it's even less.

Buy a good forged crank, and have it worked by a reputable shop. Nobody gets far with junkyard stuff.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #8 – November 13, 2013, 11:15:21 AM

the 255 crank will outlast a stock block. most aftermarket cranks are cast, and most factory ones are.forged.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #9 – November 13, 2013, 07:05:09 PM

Quote from: Haystack;424383

the 255 crank will outlast a stock block. most aftermarket cranks are cast, and most factory ones are.forged.

Even IF you can find a 255 crank that doesn't need work. IMO, it's simply not worth it. All the work to find one, then make sure it's true and doesn't need worked over. Buy a good forged crank and start with that, that way you'll know your bottom end is stable. If I was going to go that route, it wouldn't be in a stock block anyway, so the comparison is baseless.

And your second statement is ass-backwards. The run of the mill windsor engines had cast cranks. Some of the hot ones though were forged, but typically, cranks from Ford were cast.
All but the cheapest aftermarket cranks are forged, that's why there is a demand for 'em, so people can build a stronger engine.

But, it's been proven time and time and time again, a modded stock-based crank will usually outlast a 5.0 block. Or at least when the block lets go, it won't be due to crank failure. That's why I wouldn't bother swapping a crank for less than 10 pounds of weight, and then needing a witch doctor to balance the new rotating assembly all over again, and having a time of it. I've got better things to do than find a 31 year old part to put in a H/C/I combo that won't gain any more power over the stock part, to only save 5-8 pounds. Now, if it added a bit of stroke to boot, I'd only sing praise.

In short, for the gain, it's too much work for me. Have at it if it's your cup of tea. LOL.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #10 – November 13, 2013, 08:20:42 PM

Hey, if I end up doing this swap, finding a 255 crank won't be that hard for you guys

. The engine runs super and only has 71k miles on it. I am just debating on the swap since the rear main seal started gushing. If I have to pull the motor to fix that, I might as well just put the 351w in there.

I might just have a mechanic friend of mine fix the seal though. Save the swap for another day when I have enough money to do it right.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #11 – November 13, 2013, 10:15:25 PM

Quote from: ThunderbirdSport302;424397

Even IF you can find a 255 crank that doesn't need work. IMO, it's simply not worth it. All the work to find one, then make sure it's true and doesn't need worked over. Buy a good forged crank and start with that, that way you'll know your bottom end is stable. If I was going to go that route, it wouldn't be in a stock block anyway, so the comparison is baseless.

And your second statement is ass-backwards. The run of the mill windsor engines had cast cranks. Some of the hot ones though were forged, but typically, cranks from Ford were cast.
All but the cheapest aftermarket cranks are forged, that's why there is a demand for 'em, so people can build a stronger engine.

But, it's been proven time and time and time again, a modded stock-based crank will usually outlast a 5.0 block. Or at least when the block lets go, it won't be due to crank failure. That's why I wouldn't bother swapping a crank for less than 10 pounds of weight, and then needing a witch doctor to balance the new rotating assembly all over again, and having a time of it. I've got better things to do than find a 31 year old part to put in a H/C/I combo that won't gain any more power over the stock part, to only save 5-8 pounds. Now, if it added a bit of stroke to boot, I'd only sing praise.

In short, for the gain, it's too much work for me. Have at it if it's your cup of tea. LOL.

oops, your right. I ment to say stock were cast and most aftermarket were forged.

pretend your racing in a class that only allows stock displacement, the 255 crank could make a big difference. a lot of people don't like aluminium flywheels because they feel like the engine losses torque, even though it is faster. I'm sure the same would apply here.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #12 – November 13, 2013, 10:58:44 PM

Quote from: ThunderbirdSport302;424375

The 255 cranks is no more than 5 to 6 pounds lighter.

Using a 255 crank in a 600 horse engine is laughable at best. With any kind of power adder, it won't last long. We all know that stock blocks are none too long-lived anyway. Put a belt drive supercharger on there and it's even less.

Buy a good forged crank, and have it worked by a reputable shop. Nobody gets far with junkyard stuff.

well, that depends. if you are buying a 351c crank from a junkyard, and it is in good shape, it WILL handle better than 600hp despite being a cast crank.

Quote from: Haystack;424383

the 255 crank will outlast a stock block. most aftermarket cranks are cast, and most factory ones are.forged.

yeah sorry, but you corrected yourself after being admonished.:D

to the OP, dont even bother with trying to use the 255 exhaust manifolds on anything, even another 255. the stock 302 exhaust ports are small enough, but ford made the 255 head ports even smaller, with the manifolds to match. they are restrictive as heck, and even ported they flow like .

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #13 – November 13, 2013, 11:27:46 PM

Quote from: rbohm;424415

well, a 351c WILL better 600hp despite being a cast crank.

That's the standard with which all small blocks should be judged against.

I used to hang out with this chevy fan boy. He called EVERY 302 a "boss 302" even if it was some old ass generic farm equipment with a 2bbl carb and a stamped steel valve covers. He wasn't even aware that a 5.0 was also a 302 till we met.

But him and his dad both would get wound up on old stories about the old timers and their '70s muscle cars...he's get real quiet and respectful like and say.. "I tried to hang with him and that Mercury, but man oh man, that big ole Cleveland Ford just blew my doors right off".....

As I recall the son, (who I ran with for awhile) had his old 79 Chevy 4x4 pulled out of about every ditch and mudhole in the county...usually by me, till I got tired of changing axle seals and ball joints from muddin and bought a car to cruise in.

I think the summer he got his license, he went through about 4 transmissions in that truck. If you keep breaking stock stuff, you need to lighten up your go foot, or buy better parts..lol.

I'll never forget the reverence they had for the 351C though. It was almost comical. The bug eyes, the lowered voice, he'd lean forward and sing it's praises. He should've switched brand loyalties....HIS dad was a ford salesman for years and years...dunno where the dad went wrong, but he picked up chevy and so did his kid. the kid and I were in school together. He turned out to be a real bad apple though, and that's where this story ends, along with my post. Peace.

Another 255 V8 Question- Headers & Exhaust Manifold Compatibility

Reply #14 – November 13, 2013, 11:44:12 PM

the NHRA had some serious reverence for the 351c also. in fact they had so much reverence that they had some of the toughest weight breaks on cars powered with the 351c. bob glidden built 340ci cleveland motors tended to dominate pro stock racing, so much so that in 1978 glidden won both the NHRA and IHRA rpo stock titles with a PERFECT winning record, it was 32-0 that year. and to prove it wasnt just the motor, he switched to hemi power in a plymouth arrow in 1979 and won the championship again in NHRA. after that the small blocks were retired and the NHRA and IHRA went to 500ci and unlimited mountain motors respectively, and glidden STILL dominated.

and trust me, you havent lives until you have felt a 707ci normally aspirated motor lay down a mid 6 second run while you are stnding at the 1000ft mark. its almost and intense as a top fuel dragster at full song at the same mark.