1970 Mustang 428 CJ part number needed

Crisco · 10-16-2017, 06:09 PM

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 · 10-16-2017, 06:42 PM

felpro 1442

partsbob67 · 10-16-2017, 10:43 PM

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

Rory McNeil · 10-17-2017, 01:36 AM

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 · 10-17-2017, 07:27 AM

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 · 10-18-2017, 10:09 AM

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

Bret Velde
2003 SS/LA

10-16-2017, 06:09 PM	#1
Crisco Member Join Date: Jul 2005 Location: Hendersonville, TN 37075 Posts: 225 Likes: 4 Liked 44 Times in 20 Posts	1970 Mustang 428 CJ part number needed 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

10-16-2017, 06:42 PM	#2
Tim H VIP Member Join Date: Jan 2007 Posts: 1,042 Likes: 1,073 Liked 482 Times in 159 Posts	Re: 1970 Mustang 428 CJ part number needed felpro 1442

10-16-2017, 10:43 PM	#3
partsbob67 Member Join Date: Apr 2005 Location: rohnert park,ca Posts: 414 Likes: 11 Liked 79 Times in 11 Posts	Re: 1970 Mustang 428 CJ part number needed they didn't have exhaust gaskets from the factory did they? thought they were metal to metal. __________________ bob beals 7244

10-17-2017, 01:36 AM	#4
Rory McNeil VIP Member Join Date: Jun 2007 Location: from Vancouver BC Canada, now in Nova Scotia Posts: 1,311 Likes: 317 Liked 1,104 Times in 302 Posts	Re: 1970 Mustang 428 CJ part number needed 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. __________________ NHRA 6390 STK M/S 85 Mustang

10-17-2017, 07:27 AM	#5
Crisco Member Join Date: Jul 2005 Location: Hendersonville, TN 37075 Posts: 225 Likes: 4 Liked 44 Times in 20 Posts	Re: 1970 Mustang 428 CJ part number needed Thank you for the replies. Yes it still has factory manifolds. This is a restored car. I will try the 1442 Felpro. Thanks again.

10-18-2017, 10:09 AM	#6
BRETV Senior Member Join Date: Oct 2003 Posts: 567 Likes: 4,163 Liked 776 Times in 199 Posts	Re: 1970 Mustang 428 CJ part number needed We just restoed a 69 R code car and used NO gaskets metal to metal and it was fine Bret Velde 2003 SS/LA