To Head Or Not To Head, That Is The Question

While I'm pulling this motor out and cleaning everything up I was wondering if I should be on the lookout for some gt heads. I believe my motor to be an 86 block with stock looking heads except they have dual springs witch makes sense with the install of the solid x cam. This is all second hand info from po who says he got his info from the guy who put the engine together. I'm thinking that if this guy went to this much trouble and work on this engine that he probably reworked these heads and I'm not sure of the benefit verses trouble and money to change the heads.
again this is what I've been told about the engine and what I can see
Punched out 30 to 306 (found receipt for pistons under seat)
x cam solild lifters
70mm bbk tb
70mm mafs (originally air density, mafs grafted into computer wiring)
Edelbrock intake
shorty headers
bbk fuel rails & reg. (maybe soon to be changed)
not sure what injectors are in there but while I'm at the junk yard should I look for some e6 injector?
stock distributor, coil and ford racing wires
4:10 gears in a TB disc brake rear
The car ran strong before the fire and I was happy with the performance. It' s just my cruiser.
It ran strong before

I did have an oil pressure problem but it turned out to be a bad (cheap) sending unit. Replaced unit and pressure gauge is now holding at half scale

I'm only passing on what I was told, the block # indicates it's a 1985 block so it's probably not a roller but I understand they changed mid 85? Never pulled the lower intake off to check. The valve train has a little noise that sounds like the solid lifter cams I remember.