Cobra Jet Engine Rebuild for KR Convert

I put in a heat risor on a 68 pi. but could not stand the exhaust noise leak so took it out. that was fun & games dealing with those ex. manifolds.---S.

 

Did you have the Block Decked? What will the Compression be? I had a 1970 Mach 1 SCJ 4 Spd that was Bored 30 over, Decked 10 and Heads Shaved 10 and Pop Up Pistons installed. Had 13 to 1 Compression and had a very mean sounding Cam. I had to flood the Engine with fuel to get it to fire up. When I un-Capped it, it sounded like a Top Fuel Dragster idling. I think.... the cam was a 520 Lift with 290 Duration. I miss that Car........

 

Hi

I am also rebuilding the engine in my KR conv. I am having trouble finding replacement engine mounts, did you re-new yours? If so, could you tell me where you purchased yours from. I also need to replace the declutching fan, any tips on where to obtain another one?

Thanks in advance.

Paul

 

NPD has 1967 to 1970 390/428 Motor Mounts listed. Part #6038-9 at $41.95 each. FL= 1-800-847-7595, MI= 1-800521-6104, NC= 1-800-368-6451, CA= 1-800-235-3445
If you need the Block Plates, Part #6046-1A @ $124.95Pr. and the Frame Brackets are Part #6028-9-2A @ $104.95. Hope this Helps.
David

 

The D1ZZ service motor mounts are not too hard to find. Do you need a clutch or do you have one that can be rebuilt?

 

Hi guys.

Thanks for your replies and useful information.
Tlea-I have a fan clutch but I believe that although it sort of fits it is not correct (it seems to be very close to the rad). So I would be looking for the correct replacement for an auto trans. car. Any help would be appreciated.

Thanks


Paul

 

When you say replacement do you mean that, something that will fit, or a correct as in original replacement? Obviously a considerible price difference between the two. By the way trans doesn't affect clutch part # only w or w/o AC .
Tim

 

Hi Tlea

Its an A/C car. I would like a clutch that fits, the rebuild will not be to concours standards. So if you could let me know where to get the right part I would be very grateful.

Regards

Paul

 

I believe NAPA sells a clutch that will"fit". You have to be careful as a lot of vendors will sell you one but they are too close to radiator. First time you hit brakes hard the radiator will be toast. If you have your original, it can be rebuilt for not a lot more than new replacement.

 

hey mike....pull that sticker off the top of the air cleaner!!!!....you know better!!!

 

Compressor should be painted silver and have a C8ZX metal tag. The A/C clutch should be the other style(the two piece one with the donut shaped electro magnate )The one on the car is right for your 67 air car.
. The exhaust manifolds should be cast iron gray and not black.PCV fitting coming out of the intake is painted with the engine the assesory fitting attached to that one is bare brass.Breather elbow on cap is zinc gold. Alt pulley is zinc gold. The fan that is on the alt now is the 1970 style. I guess this is the time to change those things if you want it to look historically correct .I hope this helps.

 

If you want it fast NPD or Virginia mustang otherwise it is a AMK product and you can buy it direct from them but they aren't as fast. The best of luck with the project.

 

FWIW, my KR is an original a/c car, bought in '72 with all original hoses and belts. Compressor is almost undoubtedly original, with the original tag intact...it is painted black. The clutch is natural.

 

If the car was purchased in 1972 it would have plenty of time for the compressor to fail and be replaced before your purchase. The C7 and the C8ZX compressors were not serviced ,they were assemblyline only. Your car could also be a exception. I just got finished inspecting two consecutive serial number 68 KR converts that were low milage survivers type cars that had the special silver painted aluminum C8ZX compressor . They were mid KR production.One even had the C8ZX ink stamp still visible on the Zinc silver plated clutch just like the pictures I took of the white 68 KR at BJ we talked about recently that is for sale again. In the same shop is another KR A/C equiped car that is early production 22## somthing that has the one 427 low riser head and the other a CJ head (early production) . It has a C8ZX compressor.I have based my observations on many examples besides these. These are not just my thoughts but a line of thinking arrived at by pooling observations of other Shelby Judges/enthusists. I first thought for many years that only the GT350 and GT500 got the special compressor just like in 1967 and the KR being a Cobra Jet eqiuiped car like the Mustang would have a regular C8AA one like the mustang which had the same engine. The 67 Shelbys with their special engines and equiped with air were not available on Mustangs (289HP and 428 2X4 PI) . The same was mostly true with 68 with the 428 in the normally 390 equiped mustang . Not so much with the 302 equipped GT350. I thought my conclusion that the A/C equipped KR with a normal C8AA York compressor was sound because the mustang equipped car was identical. Not so . Time and time again I have seen on surviver type A/C KR cars the C8ZX compressor and clutch. I had to change the way I thought about the way the KR's were built. Now saying that I would have to concide the fact that a few anomaly's would surface but from the the evidence I would have to conclude that the C8AA black compressor would be the exception and the C8ZX silver compressor would be the rule. All of the historical photos I have ever come across support that conclusion also. Also FYI the low mileage white KR that is for sale and is so original had a compressor change to a C8AA compressor but still had the C8ZX stamped cllutch which would be normal. When replacing a faulty compressor which was serviced by itself the clutch would normally be reused. Also there would be no reason for Ford to use the C8ZX clutch without useing the companion special C8ZX compressor. There were a few distributor hoses changed along with the compressor on that car. I hope this explans the choice of compressor.

 

My KR is #2389, built Apr 30. The compressor is a C8ZX, it is painted black, and it has always been black. I conditioned my original response as "almost undoubtedly original" only because unless you're the original owner and never left it out of your sight you can never be absolutely sure. I don't dispute your reasoning about compressor replacement by '72, but you didn't see the car when I bought it, and I can tell you that it would be extremely unlikely if it had been replaced. If, over the years, I had changed something on my car because one expert or another told me something couldn't be original, a tremendous amount of what actually was original would have been lost.

 

Not the clearest picture but here's 2870 which is a fairly unmolested car showing silver painted C8ZX compressor and clutch,

On the 68 500s we typically see the C8 York natural aluminum compressors but I've seen a few black cast Tecumsehs as well