Your thrust tube does not look right, you should try to taper it down. From
the pics you provided it looks over sized and that will cost you some thrust.
Get with uncle Bob to find the correct diameter for the rear of the tube
Dave the one in the pic on the BVM site is an F-86 Sabre and they are telling you
to taper down the end to match the Sabre I dont know the specs on the Electra...

P. Richards aka SwatTeam