i agree with pschlosser... rebuild it while it's out. I also find it easier than an engine and just follow along with the instructions :) It does require a few tools you may not have around though... clutch drum spring compressor, snap ring pliers, bushing drivers... but they're not overly...
re: "electric pump won't keep feeding gas"... you can install a low pressure cut off inline at the oil pressure sensor so the fuel pump cuts off if oil pressure drops out.
i use a Holley Red... but you should check specs to make sure you get the right one for your application... recommend upgraded fuel filter and pressure gauge
my cars are 1971, cuda and challenger, butt i can't imagine 74 is much different... in the cuda i have it mounted on the left inner fender where the batter was (it's not in the trunk)... obviously not an option if the batter is still up front. On the challenger i have it mounted to the firewall...
Flowmaster does have a range of options that gives you different sounds as well... i have 40s on my challenger and 10s on my cuda.. 10s are as close to open headers as flowmaster makes (at least was when i bought them some years back)
jack makes it easier to lift but it's still not "easy" alone since you have to wrestle it up onto the jack, keep it balanced while lifting it up and wresting it into place
I have the B&M pan and no clearance issues (well, i don't go over speed bumps with the car). There's 3 inches of clearance between the lowest part of the pan and the ground
I've used Grundy for years but never had a claim. With all the mention of Hagerty here i went to their site and got a quote... was $100 more per year than I've been paying at Grundy.
IMHO, bypassing safety features, or even just features, to get around a problem just leads to more and different problems later. I would highly recommend troubleshooting and repairing the actual problem, as @pschlosser said.
not arguing against what others have said about not bypassing the radiator but i've run mine bypassed with no problems. You can always run a deep dish pan such as above and add a temp gauge to know for sure where it's running.
amazing posts there... i've got 73 spindles on my 71 challenger, installed before i bought it and unknown, and went through figuring all that out on the fly... wish i had this info back then
in addition to GOOD snap ring pliers you'll need a clutch drum spring compressor. Also search for "atsg 727 service manual" and you can find free pdf versions of it... it has detailed info on the 727/904 including step by step procedures for rebuild. Sockets with square ends would be fore...