Now for some ugly. When I got the car there was a persistent petrol smell up the front. The pump had been replaced sometime in the past with one that didnt match the input pipe, so they cut the pipe short and connected it with some hose. Problem was this allowed the supply pipe to sag and it eventually suffered an abrasion pin hole from rubbing on the engine mount (I think?). I cut the pipe even shorter to remove the leaking section, joined it to the pump with more hose, tying the pipe up to prevent any more abrasion, and sleeving the part along the block to reduce its heat exposure. Later on the mechanical pump died , so its now fitted with a Huco sucker type.
Anyway, back to now. On closer inspection of the reserve tap outlet pipe connection the plastic tubing was damaged, so that needed attention while it was accessible. Undid the clips to the pump inlet hose, unscrewed the nut at the reserve tap, removed the whole thing - much easier to fix off the car. Carefully cut the plastic hose off the fittings, and replaced it with 5/16" fuel hose and clips. Refitted the heat resistant sleeving, back onto the car, and Bob's nearly your uncle.
I now have access to the rear main seal, which is weeping, but I really dont want to drop the sump and slacken the rear main just now. the 3.9 block will get rebuilt sometime soon....and the weep is not really an issue. in fact the most persistent leak is a weep past the sump plug washer. As soon as the LT77 is in and sorted I will put the sd1 sump on and that should be the end of that leak. on checking the rear seal on the 3.9, I found the rear flange of the crank has a chamfer, possibly to make seal fitting more reliable. Going to remove the seal from the 3.9 and see if I can install a new one without difficulty, with the main cap in place and tight.