1970 Mustang 428 CJ part number needed

[Crisco]

I have a R code CJ Mustang in my shop for repairs and we are having a hard time finding correct exhaust gaskets. Would anyone happen to know a part number? Felpro, Mr. Gasket etc?

Thanks
Chris

[Tim H]

felpro 1442

[partsbob67]

they didn't have exhaust gaskets from the factory did they? thought they were metal to metal.

[Rory McNeil]

Does this Mustang have headers or the factory exhaust manifolds? Like Bob stated, 428 Cobra Jet engines did not use exhaust manifold gaskets, they were bare metal to metal. I realize that over the many years, it is common for rust a pitting to occur at the mating surfaces. On my own 428 CJs, I have had the exhaust side of the heads surfaced, as well as the exhaust manifold flanges. When bolting the manifolds to the heads, I applied a thin coat of Nevr Seeze to the mating surfaces, to help prevent later issues with pitting.
Now, if it does have headers, be aware that there are headers out there for Ford FE engines that do not have the proper exhaust port location, and will not seal up properly . The 58 up to about 1966 heads have an exhaust port location that is about 3/8" higher than MOST later heads, although the 68 thru 70 428 CJ heads retained the higher port location. Most 390 "GT" style heads had the lower location (except for the C6AE-R castings), so if the headers claim to be for a 390 AND 428CJ, theu will likely only fit 1 application properly. I have also found out that the Mr. Gasket header gaskets that claim to be for a 428 CJ do not fit properly, and because they have slotted upper bolt holes at the ends, the combination of the bottom of the slot (the 390 "GT" exhaust pattern has the upper end bolt holes located lower than the 428CJ heads), which combined with the higher exh port location, leaves less than 1/4" of gasket material to seal. With proper fitting header flanges on a CJ head, I have had good luck with either the FelPro header gaskets, as well as some more obscure companies like Ford Powertrain Applications (FPA), and Honest Georges. Ford Power Parts (FPP) also had specific 428 CJ header gaskets, but they have been out of business for some time. I have not tried them personally, but I have heard good things about Remflex header gaskets, however they are quite thick, which may cause clearance issues between the header flange and shock towers. Not much room there! The vasy majority of 428 CJ heads carry casting number C8OE-N, and have 4 bolt holes around each port, I always try to get as many header bolts in as possible to help with the gaskets sealing. Its an ugly job to change the header gaskets in the car of a FE Mustang or Fairlane, you sure don`t want to "enjoy" doing the job more than once.

[Crisco]

Thank you for the replies. Yes it still has factory manifolds. This is a restored car.

I will try the 1442 Felpro.

Thanks again.

[BRETV]

We just restoed a 69 R code car and used NO gaskets metal to metal and it was fine



Bret Velde
2003 SS/LA

[Crisco]

Thanks Bret.

I knew there wasn't supposed to be any gaskets, but the person who built the car had put them on originally. The only reason I am putting gaskets on is because I don't want to have to take it apart again if it leaks..LOL

[Rory McNeil]

To be honest, I would not use any gaskets on a 428 CJ with exhaust manifolds. You will notice that the exhaust ports of the exh. manifolds are larger than the ports in the heads, I have never seen any exhaust gasket that will match the ports of the CJ exh, manifolds. As long as the mating surfaces of the heads and exh. manifolds are flat and smooth, there should be no leaks with putting it together without gaskets. Plus the solid fit without gaskets will greatly reduce the chances of cracking a valuable and hard to find factory CJ exhaust manifold. Like I said earlier, a skim of Nevr Seeze around the port openings will help prevent rusting surfaces down the road.
Are you doing this job with the engine out or in the car? If its in the car, I have never had much luck removing, or even worse trying to install the exhaust manifolds, with everything in place. I ended up re & reing the cylinder heads with the exh, manifolds attatched, and taking off the manifolds afterwards on the bench. Plus if you need to have the heads exhaust side re surfaced, they would have to be removed anyhow. Not the more fun engine compartment to work in! Good luck.

[Larry Hill]

Not completely on the subject, but the best line I ever herd about installing headers on a street 428 CJ Mustang. " I cried three times before they were on"

[Rory McNeil]

Originally Posted by Larry Hill

Not completely on the subject, but the best line I ever herd about installing headers on a street 428 CJ Mustang. " I cried three times before they were on"

Larry, I have owned 3 69-70 428 CJ Mustangs, and 2 69 428CJ Fairlane Cobras, I don`t recall ever crying when doing the headers (or exhaust manifolds), but plenty of sweating, swearing, and bleeding!!