1991 #614 back from grave but no start, cranks just fine

[MRCFOUR]

Hello Z family! So, as you all know, #614 has been in reassembly mode since November of 2022. So, this week we decided to try and get it running. After, tear down of PS header to replace and reposition gasket so that the manifold studs could be installed, various mystery leaks involving the V drain tube, repair and verify all secondary vacuum hoses, removal and cleaning of contacts in starter, replacing ignition coils (verified spark at all 8 plugs), verifying of fire order, removal and testing of alternator, replacement of spark plugs and fuel filter and new single pump from DL Merrill (now have 50-55psi at crank with 45 and eventually lower after crank) setting of TPS voltage, and 2 different PROM chips we are at this stage?. Cranks, does not run unless throttle pedal is lightly feathered, back fire out of headers and TB, smoke puffs out of TB during cranking. Any insight would be greatly appreciated. This car has been off the road since 2019 and was bought in pieces so to be here at this stage is simply a marvel.

HELP! We are at our knowledge base limit and do not know what else to do. Replacement of injectors will be our next step unless this is something silly we are missing.

Thanks so very much!