I've done several over the years but I can't find the reducers I used to use.

These are close and should work for you.

http://cgi.ebay.com/ebaymotors/VOLTAGE-R...=item1c186a0fb5

1957 Plymouth (Hemi, Dual Quads, A833 4 Speed 9 1/4 w 4.10) Sold
1937 Dodge Pickup (Hemi, 6X2 intake, 46RH, Dana 60 w 4.56) Sold
1968 Plymouth Valiant 2dr sedan (354 HEMI, 46RH w/4.30 gears) under construction