Jetaway swap to TH350 or TH400

[R Jones]

I have a 1962 Cadillac Eureka Hearse with 390 engine and Jet Away trans. I want to convert to TH350 or better yet TH400 trans. My car is a large Hearse so I guess the heavy duty TH400 is best

Is the bell housing bolt pattern different on the Jetaway compareed to the TH350 and 400? If so do I need a trans conversion plate.  I dont think it will just bolt in although Cadillac started usung TH400 in 1964?
Also the ring gear is on the torque converter on the Jetaway so I would need a flex plate too?

Any info pleas

[Doug Houston]

Your observations are pretty true. The Jetaway has a different bolt pattern than the THM400, which would be a very wise choice. While the 63 to 64 engines were similar, the boly pattern changed for use with the THM400. Ive lost track a bit, but the Jetaway was continued on the 1964 75 (or 65?) series with an adapter plate to fit a Jetaway to a THM400 engine.  

Maybe, it would be a good choice to find a good 64 engine and THM400 and install it in the 63. I went through this once putting a 65 engine in a 63 CDV. and found that the mouinting ears on the 65 block are different than on the 63-64 blocks. It was a messy conversion.

[Ed Mobley]

Hi,

Have you considered rebuilding your existing transmission?  If not, where are you located as I wouldnt mind having an extra Jetaway for spare parts.

Regards,

Ed

[R Jones]

Doug
I just had my 62 390 engine completely rebuilt so Im not going to swap for a 64 engine.  Besides I want to at least keep that much original.  THanks for your ideas.

Ed
I live in Hawaii and no rebuilders here.  I will keep the trans (still leaks) for a spare for my 59 thouh its a hard mate up for a 62 Jetaway to a 59 engine.  (My 59 has a 61 tran in it now.  THat took brute force to line up)

Anyway it takes I will make a conversion happen.

[Paul Flykt #18899]

Try this link for an adaptor.

http://www.transmissionadapters.com/ TARGET=_blank>http://www.transmissionadapters.com/

Most of their adaptors are made to use the Chevy bolt pattern not BOP.

Have you considered a 700r in lieu of the 400? The 700 is tough enough for your 390s torque and youll keep the rpms down with overdrive.

[R Jones]

 

THanks for info Paul (http://www.transmissionadapters.com/)
I will call them.  Looks like they have a kit for TH400.

You recommended a 700r in lieu of the TH400 because of overdrive.  Does the n700r have same bolt pattern and size case as TH400?

I have a 62 Cadillac Hearse that weighs about 7,000lbs and I use it to carry alot of heavy work realted items so I need a trans that a truck would use.  I was told I should get a TH400 with shift pack also.

Aany ideas?  Also is the 700r more expensive trans?
Thanks

[Bruce Reynolds # 18992]

Dear Mr. Jones,

With that package you are trying to pull around, and the fact that you are in Hawaii, then I dont think you need to be bothered with an overdrive transmission as your roads arent long enough to warrant an overdrive.

A TH400 will be tough enough and if you ever need an overdrive, I would be looking into a Gear Vendors or a Hone Overdrive unit.

They make them to fit on the back of the TH400, or you can run it further down the tailshaft and mount it separately.

Bruce,
The Tassie Devil(le),
60 CDV

[Bob Dziewit]

The 700R4 uses the Chevrolet bolt pattern.  You will need an adapter.  It is an excellent transmission though.  Avoid rebuilt torque converters.  Between a friend and I, we have had at least four of them fail, and when they do, the transmission clutch plates are instant toast.