Converting 351C to 45 degree thermostat housing

[cudak888]

Hello fellows,

After spending two weeks chasing after a good 90-degree/straight-up thermostat housing for my 351C - and coming up virtually empty - I find that if I plan to go Duraspark, it won't work. Looks as if fate is trying to tell me something.

First of all, the stock setup of my 351 4v:

Well, seeing how hard the darn thing is to come by, I'm rather pleased - for I found that there's a drop-in workaround for this, thanks to a bit of snooping under the hood of my 400-equipped Lincolns. Ignore the arrows and look at the T-stat housing:

(Different car, same engine. The one above has the A/C compressor pulled out of it - don't let it throw you off)

The Lincoln has a 45 degree outlet - specifically, this one - which, unlike the 90 degree outlet, is reproduced in cast iron by half a dozen different companies. This outlet also clears the Duraspark distributor:

NOTE: If anyone knows the size of the plugs (I believe it's 1/8" NPT, but I don't know the diameter) I'll need to stick in the two tapped housing holes, fill me in, please!

Now, upon checking the Mustang's upper radiator hose against the Lincoln's, I found that distance between the thermostat and the radiator to be exactly the same on both cars - if the radiators aren't the same model, they definitely share the same basic dimensions.

In short, the Lincoln's radiator hose is a bolt-in fit onto the Mustang, when used in conjunction with the 45 degree T-stat housing.

Following are the parts I've ordered for the conversion:

• Thermostat housing: FOUR SEASONS #84876 (or equivalent, W2454 seems to be a popular P/N too)
  
• Upper radiator hose: GOODYEAR #60968 (or equivalent) - It turns out that the Goodyear hos is not a good fit. Use Gates #20380 and trim it to fit.
  

Photos to come soon as the parts arrive from Rock Auto.

-Kurt

 

[Totalled]

Umm, run a small points cap.

 

[cudak888]

Umm, run a small points cap.

Is the small points cap mated to a stock Duraspark unit?

Any crossfire issues?

-Kurt

 

[Totalled]

Stock duraspark dist with MSD6AL digital ignition. Haven't noticed any crossfire or spark scatter issues, and it's a hotter system than duraspark.

I think that on a cleve, that taller stat housing might make the interference worse. I'll pull the cap and adapter off of my bronco tomorrow and see how it clears, or doesn't, the stock style water neck.

 

[c9zx]

+1 on totalled's post. No need for the large cap. Just remove the large cap and the somewhat bell shaped adapter. Clip the small cap to the distributor with the clips on the distributor. I've used the Dura Spark/MSD set up for the last 20+ years on numerous cars with no problems. If you have the part number for the thermostat housing, contact Green Sales in Cincinnati, Ohio. They may have one. Chuck

 

[cudak888]

Stock duraspark dist with MSD6AL digital ignition. Haven't noticed any crossfire or spark scatter issues, and it's a hotter system than duraspark.

I think that on a cleve, that taller stat housing might make the interference worse. I'll pull the cap and adapter off of my bronco tomorrow and see how it clears, or doesn't, the stock style water neck.

I prefer the stock Duraspark box. I'll save $250 and it'll interchange with everything else I have, and I already have a few good spares - same for the cap and rotor - and I think I have a spare distributor too. Given my supply of parts on hand, I just don't see the point in spending the extra for the MSD parts. The large cap doesn't bother me a bit (unless it won't clear the air cleaner - in which case, I might have to get a similar cleaner from a later 460 and dress it to look like the one off the 351).

The 45 degree outlet shouldn't make the interference worse - the only difference between the two blocks is deck height (400's are taller). The T-stat outlet height on the blocks are identical, as is the distributor position.

If anything, there will be more clearance with the 351C; the only thing that I might have to alter is the coil bracket - I believe the bracket is taller on the 400's to clear the T-stat housing.

...if you have the part number for the thermostat housing, contact Green Sales in Cincinnati, Ohio. They may have one. Chuck

Way ahead - already tried there too. The NOS, $100 + $40 shipping Aussie part is the only decent piece available in steel.

-Kurt


Though I have the Goodyear hose on order, I test-fit a spare Gates upper hose that I carry in the '79 Continental's trunk.

It looks as if it would need some trimming, but will fit fine. I was quite surprised that it wasn't a perfect fit though, and checked it against the Lincoln. Sure enough, it looked as if it's cut a bit long for the Lincoln as well. I don't foresee any problems.

-Kurt

 

[Wolverine]

Remember, the DURASPARK cap has posts. The standard small cap has sockets. So, you would have to change out the wires if you go to the small standard cap.

Unless you can find THE standard small cap with posts....

 

[cudak888]

Remember, the DURASPARK cap has posts. The standard small cap has sockets. So, you would have to change out the wires if you go to the small standard cap.

No problemo - I've got a set of spare Duraspark wires in the shed.

-Kurt

 

[Wolverine]

By the way, this is a nice retrofit.

Not sure which is harder to find though...the Mustang radiator hose or the Lincoln radiator hose. I will have to price them out to see.

What year(s) Lincoln?

 

[cudak888]

Not sure which is harder to find though...the Mustang radiator hose or the Lincoln radiator hose. I will have to price them out to see.
What year(s) Lincoln?

Rock Auto carries both (and thankfully, amongst all the flex hose are the proper formed ones). Anywhere from $10-22.

1978 or 1979 Lincoln Continental (or Mark V) with 400 CID 6.6. Easy as pie to find new hoses online for it. Ditto for the 45 degree t-stat housing.

-Kurt

 

[cudak888]

All the parts for the conversion arrive tomorrow. Will post photos.

I also realized the '71 coil bracket won't clear either. Just purchased one of the extended-height coil brackets for the 400/351M:

http://www.ebay.com/itm/1973-74-75-76-77-78-79-80-FORD-COIL-BRACKET-73-1974-1975-1976-1978-1977-1979-/120991241957?pt=Vintage_Car_Truck_Parts_Accessories&hash=item1c2ba3d6e5&vxp=mtr

-Kurt

 

[woodsnake]

I have never seen a small, early style cap, with the posts, for the modern plug wires. I've only seen the "female" style.

If there is a small cap, that can use the newer style wires, please let me know where to get it!

 

[Totalled]

It will fit with the standard water outlet and mustang hose. It just barely contacts the hose, and would probably clear if the hose was trimmed shorter.

 

[cudak888]

More frustrating news:

The Rock Auto part (4 Seasons 84876) arrived. It's aluminum.

I tried ordering the "steel" one from Jeff's Bronco Warehouse. They cancelled the order. It's aluminum.

I went on eBay. They're aluminum.

I found one NOS Autotemp W2454 on eBay today which looks as if it MAY be steel, so I ordered it anyway.

Wouldn't you know a decent, steel, 90 degree outlet popped up on eBay in the meantime? Haha!

-Kurt

 

[cudak888]

On a better note, I received the 351M/400 coil bracket today - this particular bracket mounts the coil a bit higher and at an angle in comparison to the 351C bracket, thereby giving the 45 degree housing and hose a bit more wiggle room:

-Kurt

 

[cudak888]

One other thing I forgot to mention - the Goodyear upper radiator hose was not a good fit at all, so I tried a few of the spares I had kicking about. The Gates #20380 (interchange says it's for a '74 Torino/Ranchero/Thunderbird w/460) is a very good fit, and should require minimal trimming at each end:

-Kurt

 

[Wolverine]

One other thing I forgot to mention - the Goodyear upper radiator hose was not a good fit at all, so I tried a few of the spares I had kicking about. The Gates #20380 (interchange says it's for a '74 Torino/Ranchero/Thunderbird w/460) is a very good fit, and should require minimal trimming at each end:

-Kurt

Would that Goodyear be a good fit for a 90 degree water neck, or only the 45?

 

[cudak888]

Would that Goodyear be a good fit for a 90 degree water neck, or only the 45?

The correct Goodyear hose for the Mustang's original 90-degree neck is the #60866, shown here above the Lincoln's upper:

#60968 is for the Lincoln Continentals.

I'll probably be tossing all the excess bits that I wound up with (a spare aluminum 45 degree neck, the #60866 hose, and probably some other stuff I can't remember) on the FS forum, but if you need that upper hose, send me a PM.

-Kurt

 

[Tnfastbk]

Do you have an ALUMINUM phobia?