Which headers with a 351?

[GregR]

If one was to use a 351W in a mark IV, which headers can be used? Are the FFR 4 into 4 headers the only ones that will work? Or will the fox body 5.0 headers or 351 swap headers work?

Thanks.
Greg

[BigLeo69]

he has some sweet tuned ones if i had a choice i would go that route.
and if you get aftermarket heads with the extra head bolts then the installation is a breeze, sockets fit wrenches fit.

hooker has the 4nto4's

[Lex]

The FFR 4x4 headers are a straight shot to the body cutouts. The others are shorty headers and you have to use the J-Pipes with them.

[Rscocca]

I got a set of Gordons custom headers in a 3.1, 427W . Very nice pieces, sound amazing with a deep throatiy sound.

http://i995.photobucket.com/albums/af80/rscocca/DSC00257.jpg

[Rscocca]

Passenger side,

http://i995.photobucket.com/albums/af80/rscocca/DSC00260.jpg

[Howard]

This is a real sore spot for me - the Hooker headers that Factory Five supplies for 351Ws are terrible. They are cheap mass produced garbage. My first set had numerous exhaust leaks and this is with a soft graphite gasket (Remflex). I sold those with the plan of buying a set of stainless steel ones from a vendor - either GasN or another guy from Florida - unfortunately neither of them have a header in production yet - I was told by both of them last year that they would have something ready for market, but so far nothing. So I ended up getting another set of Hooker headers from Factory Five. The first set arrived with basically no packing around them - I have a thread around here somewhere with photos - there were gouges in the headers from clamps used to bend them etc. The header flange was off by about 1/8" - a straight edge rocks up and down across the flange by 1/8" - really poor quality. I sent those back and received my second set of headers - I asked them to add extra packing before shipping, so they arrived intact, however the header flange looks like it's going to leak big time again - there are divots cut into the flange which I know are going to leak. I'm trying to decide whether to send them back again, or mount them again and see if they will leak again. My car had a terrible time backfiring on decel from the leaks, and I don't really want to deal with that again.
Very frustrating and disappointing.

[neilmathieu]

Very nice side pipes ; where do you get the heatshields on them ?

I bought a complete kit Mark IV with 351W stroked 427 , FFR furnished Hookers headers and chromed side pipes. Now I am looking for heat shields.

[Howard]

Here's a pic of the header flange of the new set they sent me - do you think these are going to leak??? There is a divot that has been reamed at the corner - I guess I'll just goop it up with RTV and hope for the best?

http://img.photobucket.com/albums/v610/cobradvm/Uploads%20via%20Pixelpipe/header.jpg

[efnfast]

send it back

[BigLeo69]

i new if i posted you would set up with some great photos.

Howard what you need to look at is the cyl. head flange too they are very close to making a good gasket seal my RHS heads just had enough to seal.
pray they don't leak i used copper rtv and stage 8 locking header bolts, each one just about had to be hand fitted for the clip to clear, thats why i like Gordons, room to play and secure.

don't know how much though?

[Gordon Levy]

Howard, my advise if you want to use those headers is to take them and have call the flanges milled and assemble with hi temp gasket sealer and not gaskets. My complete exhaust systems run from $2995-$3995 ceramic coated depending on the system. We are currently working on a properly tuned 302 based exhaust system that will support as much hp or rpms you can produce.

[Rscocca]

Very nice side pipes ; where do you get the heatshields on them ?

I bought a complete kit Mark IV with 351W stroked 427 , FFR furnished Hookers headers and chromed side pipes. Now I am looking for heat shields.

Here is the site I got the shield from:http://www.steelshields.com/products.html#cobras

[Darren]

Howard, one of my flanges was warped over 1/16" and it pulled back in when I assembled them. Not happy about it but it sealed up. I used no gaskets, just high temp gasket sealer with no leaks.

[Brian Z]

The 351 can use either the 4 into 4 headers we carry or a aftermarket shorty header to bolt a 351 into a fox body mustang and our j-pipes. I have seen that Mac carries a shorty header for that application.

Best regards,

Brian @ FFR

[Darren]

Brian, I think you'd find most of us would be willing to pay extra for decent headers for the 351w. Mine are hopeless. I can't get to many bolts to tighten them on either side (can't get a wrench on them due to proximity to the tubes) and some can't even go in the holes period because of the proximity to the tube. Truly poor design on Hookers part.

[Brian Z]

Send pictures to tech@factoryfiveracing.com showing the problem. We can forward them to Hooker. Any after market header is a pain to work on. I have had many after market headers for mustangs, but if they are truly defective Hooker may be able to swap them.

Best regards,

Brian

[Someday I Suppose]

Darren, they are a real PITA to get a wrench on for sure. I used header bolts that have the hex head as well as an allen head and on most of them tightened up with the allen wrench. I also found it a heck of a lot easier to work on them with the valve covers off. I have the big pent roof covers and with them on there isn't much room to get down to the header bolts.

_Scott

[Joe]

That divot on the upper left looks especially bad since it extends all the way to the edge of the flange. I know FFR / Hooker can do better than that! Send em back!

http://img.photobucket.com/albums/v610/cobradvm/Uploads%20via%20Pixelpipe/header.jpg

[Darren]

Darren, they are a real PITA to get a wrench on for sure. I used header bolts that have the hex head as well as an allen head and on most of them tightened up with the allen wrench. I also found it a heck of a lot easier to work on them with the valve covers off. I have the big pent roof covers and with them on there isn't much room to get down to the header bolts.

_Scott

Yeah, I have Percy's and had to toss em. I used FFR's supplied bolts but couldn't get a couple in. I'll have to remove the headers to do so. I may end up trying to find the hex/allen combination but was set on the Percy's since they were locking. What a waste of $100. There is no way to use Percy's with these headers. I've ground down wrenches and tried everything.

[Rscocca]

You can use the Percy units if you are willing to grind ever so slightly at the bolt hole to allow the Percy bolt to slide thru at a little angle when header is loose.
Start the bolts that are on the inside of the tube bend first then follow with rest. I've used and still use the Percy bolts without problem. I use them in compo with Remfelx gaskets and have no leaks.

[Darren]

You can use the Percy units if you are willing to grind ever so slightly at the bolt hole to allow the Percy bolt to slide thru at a little angle when header is loose.
Start the bolts that are on the inside of the tube bend first then follow with rest. I've used and still use the Percy bolts without problem. I use them in compo with Remfelx gaskets and have no leaks.

That won't do it. I can get all the bolts in finger tight, there is no possible way to get a wrench on probably 3 bolts per side. They actually touch the header tube... no box end wrench will ever get around it. Even ground down to the point of near failure.

[cwhoofgator]

Ping Joey @ Performance Automotive. VERY nice 351 headers...

[Someday I Suppose]

Darren, mine are the stage 8 bolts, but ask me if I got all the tabs and locking clips in place, rofl.

[Darren]

Darren, mine are the stage 8 bolts, but ask me if I got all the tabs and locking clips in place, rofl.

He he, I understand. I'll probably just go with hex head bolts.

[Howard]

Joey has already shipped me a set of his headers for a 351w to see if they fit - they weren't even close to fitting. Georgie at GasN doesn't have any ready either.

[GregR]

The 351 can use either the 4 into 4 headers we carry or a aftermarket shorty header to bolt a 351 into a fox body mustang and our j-pipes. I have seen that Mac carries a shorty header for that application.

Best regards,

Brian @ FFR


Thanks for the help.

[Darren]

Joey has already shipped me a set of his headers for a 351w to see if they fit - they weren't even close to fitting. Georgie at GasN doesn't have any ready either.

We test fit them on mine as well and they were way off there too. The exit location for the side pipes were off and the footprint was far too large hitting the footboxes making it impossible to mount.

I'd buy a pair in a second if the footprint and fitment were accurate as his work is superior. A true work of art.

[jerrylogan]

I have the 351 4X4 factory headers after 6K miles they were still tight when I pulled the engine for a full rebuild. I use a MAC 7/16 angle aircraft open end wrench. and it does take work but I can get all of the bolts tight and they stay that way. No leaks with gaskets no rtv.
Jerry

[Don]

This is a pic of how poor the quality of the flanges are on the hookers...I will have to take mine in to have the flange sanded flat. Without that done, attempting to get the headers to seal is a joke.

http://i573.photobucket.com/albums/ss172/donandcarlynn/2011%20January/photo.jpg

[timp2]

I had the same problem with flange warpage, mine were 1/8 inch end to end on my original set and they started to leak and backfire in short order. I returned them to Factory Five and they sent a second set. The flanges were warped a bit but not nearly as bad as the first set. I sawed through the flanges where the large holes are, that allowed the two end pipes to flex and be drawn into the head. I used Remflex gaskets which are great gap fillers. I switched to 1" long stainless allen screws. I purchased a set of allen screw drivers that have a hex shaped ball on the end that allows one to approach the screw from a slight angle, The job was not easy but it did solve all of the problems that I had originally.

[neilmathieu]

Thanks Rscocca