[TheRktmn]

I have a '69 XR7 and am building a 460 for it.
I have seen the "conversion kits" offered in many catalogs, but I have never
seen a '69 or '70 that this has been done on.
Basically I am wondering how good the conversion kits are.
It is supposed to be a bolt-in conversion, but I have had people tell me that the shock towers need
to be modified.
Can anyone offer any insight?

 

[Cougrrcj]

I thought seriously about putting a 429CJ into my 'alpha' '73, but after looking at all I would have to change to do the swap (and 429s were an factory option in 71), I decided not to go through with it . Just too much hassle!

I had found the 429CJ for a heck of a good price ($250). But once I calculated the new motor mounts, transmission, headers, belts and hoses, radiator, intake and carb (I really didn't want to use the QuadraJet found on stock 429CJs) I figured I'd have well over $1,500 in just the swap alone. I put that money into a killer rebuild of my 351CJ instead.

OK, so I don't have killer big block torque, but I still turn a high 12 second pass in the quarter!

I have a friend that did do the big block swap in his 71 Mach 1. Was it worth it? I can't say for sure, but now, with a 514-inch, roller cammed, aluminum CJ-headed motor he is running 10.90s with an all-steel car with the full factory interior. He ran low 12s with the 'normal' 460.

Hmmmmm. Low 12s with a 460 or high 12s with a 351. The choice is yours!

 

[CougarAOD]

I have a 460 in my 70 Cougar. Honestly, it is a tight squeeze without cutting the shock towers. I did cut and weld my towers to ease access to the spark plugs and header bolts, but it will fit without cutting. The kit I bought came from Crites Restorations. They are the only ones that have headers for use with power Steering. The headers do hit and had to be dinged and tweaked to fit. Personally, I am gonna go back with a set of manifolds---I drive the car daily and can no longer stand the sound of exhaust leaks. Please note, these are 10 piece headers. So, unless you cement everything together they are going to leak. Another reason I'd like to get rid of the headers is that I really don't need the excess heat under the hood.
I also moved my radiator forward about 2 inches to give enough room to put the electric fans on the inside---where they are more efficient. Unfortunately the swap mounts moved the engine up and forward so you can't use a fan on the pulley. Although a place called MPG Head Service offers swap mounts that don't lift the engine (no P/S) and if you use a 69 T-Bird harmonic dampner and water pump, then there may be enough room without moving the radiator forward. Please beware when dealing with MPG Head Service/Cam Research, I have had a lot of trouble with them.
I have no regrets on doing the 460 swap. Everyone ooooohs and ahhhhs over it at shows---in the SSCC, I am the only one with a 460 that goes to shows. It is really the best part about my car. I had installed an AOD behind it and are currently getting 17 mpg's on the highway. But, that doesn't mean too much because right now the engine has a very mild cam in it.
Good luck with whatever you decide,

 

[modifiedmark]

I think I like my idea of a dart headed 393 ci windsor even more after listining to you guys. It sounds like a lot less hassle and I had a dart headed 377 ci windsor in a dirt track limited late model once and trust me it would really run. The only thing holding me back is my bank account right now but I plan on it being next winters project.

 

[TheRktmn]

CougarAOD: Wow. Thanks for all the info.
I was not aware that the kit relocates the engine that drastically, nor that the headers are a jigsaw puzzle. Glad I saved those manifolds!
My brother in law has a 69 Mustang that he converted from an FE (428) to a 460 about 20 years ago but he butchered his shock towers because someone told him he had to. There were no conversion kits available back then. Looking at it now it does not look like the 'modifications' were necessary.

Cougrrcj & ModifiedMark: I know where you're coming from. My last 69 had a 351W-2V that I replaced with a 351C. And it did perform at the strip, but free Torque and HP is hard to pass up : ). I already have the 460 and most of the "goodies" for it as well as a C6, rebuilt and ready to go, and after taking a few rides in a Big Block to compare to my Small Block experience - I am hooked!

 

[Guest]

I HAVE A '68 XR7 WITH A 429 AND IT DOES FIT WITH OUT MODIFYING THE SHOCK TOWERS.I DON'T KNOW HOW THE CONVERSION KITS ARE THOUGH. I USED THE FRAME SIDE OF A FE BIG BLOCK MOTOR MOUNT WITH THE REGULAR 429 MOTOR MOUNT ON THE BLOCK AND IT DIDN'T MOVE THE ENGINE FORWARD ANY AT ALL.ITS NOT EASY ,BUT IT'S WORTH IT . ONLY PROBLEM IS THE MOTOR & TRANNY GO IN & OUT TOGETHER BECAUSE YOU CAN'T GET TO THE TOP BELL HOUSING BOLT.

 

[TheRktmn]

429XR7: Thanks for the input. I had heard rumors that the FE/429 mounts would work, but you are the first person that has come forawrd with first hand knowledge. I was not crazy about moving the additional weight any further forward than absolutely necessary. What do you run for exhaust - manifolds or headers? CougarAOD told me that his multipiece headers leak and he is going back to manifolds. I have found a set of headers that are pre-assembled and work with P/S & A/T but I don't know if the weight savings and any additional HP are worth the expense and the additional heat you get from headers....?

 

[Guest]

I WAS USING STOCK EXHAUST ,BUT I TRIMMED BACK MY SHOCK TOWERS WHEN I HAD A FE IN IT. YOU CAN GET CONVERSION HEADERS THAT WILL FIT IF YOU LOSE THE P/S. THATS WHAT I'M GOING TO WHEN I FINISH MY REBUILD. ALUMINUM HEADS LOVE HEADERS !?!?!?!?!?

 

[Guest]

ALMOST FORGOT, MUSTANGS UNLIMITED HAS HEADERS FOR ABOUT $400 . SUPPOSE TO FIT WITH P/S & AT. DON'T WORRY COUGAR & MUSTANG ENGINE COMPARTMENTS ARE THE SAME . AS FOR THE HEAT YOU CAN ALWAYS WRAP THE HEADERS IF IT GETS TOO HOT.

 

[TheRktmn]

Those are the headers that I had in mind. By the way, has anyone else noticed that the difference between Mustang parts and Cougar parts is just $$$? My father has a 66 Mustang and my brother in law has a 69. I usually look for the parts that I need in their catalogs because they're cheaper. Thank goodness for Ford's Parts Guide!

 

[sixt9coug]

what kind of headers did you wind up going with anyway Bob? im still planning on a 460 swap for the next cat to be dragged in

 

[TheRktmn]

I used the FPA headers. There are pictures of them in my gallery.