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1990 Ford Mustang LX 351M powered!! Project Cherry Bomb!!
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Discussion Starter #1
Yeah.... I know prolly a goofy ass question, but I got a 90 LX with a 351M and I'd like to try to put a set of headers on it, but there's no way I can afford to have a set of custom jobs made for it and I can't weld ( frakkin pacemaker). What I've been looking at is a set of Patriot Exhaust H8435-B clipster headers. Or a set of the Cleveland midlength swap headers from the good people over at B&B.. the biggest issue I have of course is the taller deck height of this beastie, but ya gotta work with what ya got eh? Anyone out there have any luck or any input that may help or point me in the right direction to help this thing breathe? I do have a head swap planned later on as $$$ will allow but if I can't get the bad air out it's not gonna help much to cram more air in it eh? Any suggestions are welcome!!!
 

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1990 Ford Mustang LX 351M powered!! Project Cherry Bomb!!
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Discussion Starter #2
If it helps any, the engine was originally in a 78-79 truck according to the valve cover sticker and still have the factory exaust manifolds, the passenger side was clearanced a lil bit at the outlet.
 

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Where are you located, what you'd like to find is a header to test fit, because nobody makes a swap header for a 400/351M into anything. I have parts, one set of old 35`C-2V headers, but I'm planning to use mine to test fit for a Ranchero I have.

The 10.2" deck 400 blocks are very heavy. I'd yank that engine and sell it honestly. The trouble to get any power out of that will be disappointing and the car will always be extra heavy, with poor handling and fuel economy. Those all had 2V heads and low compression, poor small intakes etc. Mixing some old better parts from other Fords was the way to go 30 years ago, but now it's easier and cheaper to make more power with any 302/351W based engine.
 

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1990 Ford Mustang LX 351M powered!! Project Cherry Bomb!!
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Discussion Starter #4
Oh I understand the Windsor based power plants are a lot easier to work with, but I really don't have the resources for an engine swap. Just got a gravel driveway and I'm disabled (yeh great fun!). I'd planned on an intake swap and later on a set of Edelbrock or TFS heads with a cam to wake it up as best I can without having to get into actually ripping it out. If it gets to that point I'mma just do a big block swap since it's already got a C6 with the right bellhousing pattern. Maybe by then I'll be able (have the resources) to swap out the engine. That being said I also know most of the mods I'd like to do to it will be chocked out unless I can get it to breathe. Previous owners did run dual pipes on it but they are only 2 inch diameter which I know will need to go to at least 2 1/2 and I'm hoping that I can get headers to fit here's a couple of pics of it'll help give a lil perspective of the room I have.
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It is impressive that someone got that engine in there.

I wouldn't spend big money on aftermarket heads given the under 9:1 compression. I'd bet for similar money you could find a used 351W that could be comparable to the power level the heads you are considering, might get you.

Those 351M's were in the mid 150rwhp range when new. The flat tappet camshaft and small intake, low compression, and now old age, will likely limit the potential to maybe 250rwhp(if it had much better heads, intake, and cam). I'd think most used 351W's you could find should be there potentially with decent stock level parts. I'm talking about a Lightning parts level, not a mid 80's old police 351W that has flat tappets and a small intake, E6/E7 level heads etc.

Even just a stock roller 351W short block with GT40 style heads and decent intake should be better than what a 351M might do(stock short block). If you get there with the 351M, you will be at the limit of performance, and quite a bit of money invested.

I love Cleveland heads, truthfully, but the 400 block platform is really poor. I had plans to build a 408 and 4V heads, Torker 351C intake, high compression, but life happened. Over time what was a good idea in 1988, isn't anymore.

Keep that car going for a while, and see what you might find for a roller block 351W to work with.
 

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1990 Ford Mustang LX 351M powered!! Project Cherry Bomb!!
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Discussion Starter #6
Oh I know it'll be a lot lighter and easier to build say a late 80's early 90' truck 351W roller and I will keep an eye out for one. That being said, I'm also gnna try an have a lil fun with this old M and I'll keep an eye out for a big block as well. The big block would actually be an easier swap for me as it's already got the right tranny and I'll have to have an automatic because I'd have difficulties with a stick as I am disabled. I've sorta always wanted to do a big block swap even way back when I had a '79 Mercury Zeypher with a hopped up 302 and a full Mustang GT suspension under it back in the late 80's!! At that time I had a 429 to go with but I never got the $$$ for the swap parts, then... Life happened and I had to sell "Gandolf the grey". Since then all my big block parts have disappeared.. sigh But I will keep an eye out for any Windsor 351 parts and see if I can make that swap happen as well. It'll just take time and $$. And I can always sell the old M to someone with a late 70's early 80's Ford truck or Bronco after I do a lil work on it!
 

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That's a good plan. The 460 has a few Fox swap parts available, the headers would be nice to be able to find. A C6 is a strong trans and can handle whichever bigblock engine you end up with. Yes the 351 would need a different trans, I forgot you said you liked the one you have.
 

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The 351M is a D-O-G. However it is really just a tall deck Cleveland in many ways. In Hot Rod a bunch of years ago I read about a 400M that pretty good power with heads, a cam and an intake. Some stroking also helped. As with every Ford it seems, the power is locked up in the induction package. You could look for headers on eBay, Facebook Marketplace or your local Craigslist.

A 351W will be cheaper and easier in the long run. Any you-pull-it yard will have at least a few 351W powered trucks to choose from. Roller 351W are, IMO, over rated. They have a potential crack in the cam journal that non-roller eniges don't have.

 

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1990 Ford Mustang LX 351M powered!! Project Cherry Bomb!!
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Discussion Starter #9
Yeh when I first found this one it was advertised as having a 400 in it but when I looked at the sticker on the valve cover it said 351M. The guy I got it from bought it like this and let it set in a garage for 10 years!!!! Never ran it!! It's got 97,000 actual miles on it and underneath it looks like it's brand new!! No wrinkles, no rust, all the body panels have the VIN on them, it was never in any wrecks, aside from the engine swap it's really a Cherry!!! The inside shows wear and tear from sitting so long, and I've got the gas tank out cause it's just a rust tank now. But aside from things like that I had to jump on it cause of the shape of the body and the underneath of it. So even if I don't keep the 351M I have a really good starting point with a car that's got really good bones to it!!
 
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