Your pushrod lengths will be around the 7.550 and 8.550 range, probably exactly. If you can find a set of 454/502HO take-outs, the'll be real close to what you need.
Something like this even:
http://cgi.ebay.com/ebaymotors/BBC-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
Something like this even:
http://cgi.ebay.com/ebaymotors/BBC-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories