Okay i've done the search thing and not found what I was looking for so decided to ask. Back in July I had this issue:
Rebuilt 95 KADE in 93 body last april, drove it from AL to FL from 12 noon to 8pm, what is usually a 4hr drive took me 8hrs, car kept sputtering as if no fuel and eventually i waited until around 7 when it cooled down and it drove perfectly. FL to MO in june and driving at night, trip went fine.
July last year when it was dumb HOT the car would sputter and bogg on the way home at around 5pm, its a 7 mile drive, it would take 40 minutes to get home. Now again this year its doing the same thing.
An old timer told me the fuel pump was vapor locking, is there such a thing?

Last friday I changed the Knock sensor (it was cracked), the oil valve thing next to the alternator (new One in), checked all wires to be sure they were servicable, added a can of Seafoam to &filled the tank. Drove the car sat and sun no problems. tues evening it stalled and realized the intake pipe came loose, while fixing i checked oil level & it was below LO mark, filled up with Mobil 1 synthetic.
Now the car hesitates when I get on it(bogs at first then takes off), punching in 2nd gear i get a white puff of smoke, only hard acceleration in 2nd and 3rd gears.

Buddy said head gasket, im thinking valve seals. Dont want to rip it apart if idont have to, between 5-5 job and 5-10 night classes i'm strapped for time.
What can my issue be? I really need your help guys as this is my only good weekend off to get this fixed. Thanks