Fuel pressure dropping while driving and under acceleration to zero at idle runs 4 lb electric Blue

I get almost the same thing on 100 degree days. Might be vapor lock or getting close to it.

Had a Holley Red that was fussy, switched to a Carter 4070(?) and it slowly gets hot where the Holley would just stop working. The Holley didn't like being a lift pump at all while the Carter tolerates it a little