390 crank

[javpwr]

Hi,

First I want to say Hi since I'm new here.
My question is about 1970 390 crank. I know about the spacer for a 727 but is there anything or away to modify the crank to work with a turbo 400.

Thanks,
javpwr

[jeepsr4ever]

at the end of teh crank is it flush, have a small hole or a large hole. I think tufcj or fuzz401 might know the answer better than i do

[tufcj]

The only mod to fit a TH400 is to have the hole in the back of the crank made the same size as the 74-up cranks. I'm not sure of the diameter, but I can measure. On the 74-up cranks, there was a small bushing installed for the mopar trannies. You will also need to have the TH400 flex plate balanced for the 390.

[fuzz401]

I thought the small spacer was for the th-400 and had to be removed for the tork flight trannys - the th-400 has a smaller button then the 727

[jeepsr4ever]

the th-400 used the spacer ring in the crank in jeeps...not sure about cars

[javpwr]

Thanks. I already have a th400 behind a 401. It's just that I have the 70 390 and wanted to make sure the crank would work in a 401. I don't have the spacer and have no problems.

P.S. Great website. Fast help. I'll enjoy coming back.

[tufcj]

Thanks for keeping me honest. :t: I was thinking backwards, the spacer is for the GM tranny, no spacer for the Mopar.