Well... Have had the car on the road about 5 days since getting it. Runs not bad considering it's a 305.
Last Thursday I had driven about 2 hours and while on hard acceleration in 2nd it chugged a bit. I feathered out the throttle a bit and all seemed normal.
It was about 28 celcius and sunny outside.

Today, it was hot here. Well over 30 celcius on the pavement. I had it stumble and stutter once leaving town. Figured it was like the last time and wouldn't happen again.
30 minutes later, getting on to the highway with some normal acceleration and it did it, but for a longer period. Then ran fine.
About another half hour in, I was in HEAVY 401 traffic (one of the busiest highways in North America) and it did it with traffic going so slow as I was getting on the gas to make it across a few lanes to get to my ramp. Pulled over, put it out of gear and revved it... Situation normal.
Get back on the highway and I have to be gentle to it to not get it to stutter on me, and nurse it to Canadian Tire. Go inside for a few minutes trying to see what options I had... Nothing. Probably in there 20 minutes. Come back out, test the car in the parking lot and it feels alright. So I took it back out, a couple instances of stutter if I go over about 1/2 throttle.
Get on the highway, and as the temperatures outside go down, the better the issue got. And at the end of my 7 hour drive, temps are about 26 or so. I could nail the throttle and it was totally fine.

Makes no sense... All I can figure is vapour lock. What's your opinion?

It's an 87 T/A, and pretty sure it has the carb "blower" after reading the bulletins on here regarding the issue... I was wondering what that fan noise was since it wasn't coming from the radiator!

 

No, it's not "vapor lock"; that hasn't been an issue with any fuel sold in the last 40 yrs or so.

30° is NOTHING. It was hotter than that here yesterday, and besides that it wasn't even a particularly hot day here AT ALL, I'm not even in the South any more. All in the southern part of the US the temp REGULARLY gets up over 40°C.

Whatever issue you may have, if any, it isn't "vapor lock".

I'd suggest checking on the normal tune-up type things. Maybe change the fuel filter.

 

First thing I would do is replace the fuel filter, and cut the old one open and see if it's blocked at all (ask me how I know).

 

Yep, gonna check the fuel filter, new plugs and a set of wires (found one that had rubbed and has a crack in the insulation) once I get time (moving this week).

Had the car out the other night... Ran totally normal, aside from a little bit of bog when I was aggressively accelerating and turning hard through an intersection from stop (was trying to spin the tires a bit).

If I feel motivated I'll rebuild the carb, but considering I'm only going to drive this thing for about 3 more months before I put it in the garage to start doing a swap, I really just don't want to throw money at it.