to cut to the chase.... my questions are..... what s the biggest core size that will fit in my 67 skylark? did the 67 gs have a bigger radiator? whats the biggest size radiator people on here run and how much modifying did it take to fit a bigger one? i have a 67 skylark i put a 70 455 in years ago. it is in Connecticut and i moved to Texas 2 years ago, im ready to go get my Buick finally, but before i road trip it 2000 miles i need to fix a few things. one thing was i had a slightly leaking radiator before i parked it and need to replace for the Texas heat. it is a factory ac car and all ac works properly and i use it unless its too hot out and engine temps climb. so the car is 2000 miles away so i can not measure anything. i want to order a radiator and have shipped to the car so i can fly home, install it and drive to Texas. a few years ago i was running a ta performance high flow water pump and it dropped temps 20 degrees. ive changed it to stock since then but had it on when i tried the aluminum radiator im talking about below. ive been running a 180 degree, robert shaw style thermostat the whole time. then i got a 1" tube, duel row aluminum radiator with shroud and electric fan. it was a direct replacement, for my factory size radiator that came out of it, i had to order a different radiator. i believe it was for a 67 nova. a 26" core. it dropped in and worked great at idle and in traffic, but at highway speed temp would climb. i tried adjusting carb, timing, nothing helped. everything pointed to too small of a cooling system, or to fast of coolant flow with the high flow water pump and 1" tube radiator. i remember thinking a double or triple pass radiator might fix it. or a stock flow water pump. i ended up pulling it and putting the old 3 row leaking radiator back in and have run it for years with no issue other than needing to add coolant every few weeks. i remember when i ordered the radiator, and now in my searching, every single company said 67 skylark has a 33" core, well my dad has a 68 chevelle we did a whole cooling upgrade to it and i remember trying to fit his 33" core in my Buick and it wouldn't even kinda fit. think i remember it hitting frame rails as the worst part, being covered by sheet metal on core support, and just would not work at all without serious cutting. i would love to be able to fit a 33" core in my buick, it would really help. but i need to know what size to order for my car. so my questions are..... what s the biggest core size that will fit in my 67 skylark? did the 67 gs have a bigger radiator? whats the biggest size radiator people on here run and how much modifying did it take to fit a bigger one?