Try a 280z hood. My 240z with SBC and headers creates high engine bay temps. With a 3000 cfm fan you can feel the hot air blasting past the driver's door while sitting at a light as air exits the hood vents. Some people have installed fans under the 280z hood vents.
Update:
I have recently experimented with Carbotech AX6 pads.
See: http://forums.hybridz.org/topic/127572-carbotech-ax6-pads-for-toyota-240sx-calipers/
Ref: 1972 240Z daily driver
Brake setup:
Front: 1979 Toyota 4x4 pickup Calipers on solid 240z stock rotors
Rear: 1989 240SX calipers on 300zx non-turbo rotors
Master cylinder: 1979 15/16 280ZX
Booster: 1977 280Z
Since installing this brake system in 2009 I have been experimenting with brake pads:
Porterfield R4S: Poor cold bite in traffic. Removed after about six months to try Hawk Blues.
Hawk Blues: Poor bite at all temperatures. Removed after about one month to try Axxis ULT
Axxis/PBR ULT Ceramic: Good cold bite on first stop and in traffic. Ok in traffic and mountain driving.
Carbotech AX6: Excellent cold bite and bite gets better with each stop. After about four stops these pads grab hard.
Carbotech AX6 pads: Very little pressure on the brake pedal is required with this brake setup. I have smoked the fronts and the car hauls down fast without a hint of brake fade after several hard stops.
At this point I am leaving the Carbotech pads on.
Contact Carbotech to purchase pads: Ask for club 5% discount.
1979 Toyota 4x4 pickup: CT137-AX6 $141.00
1989 240SX: CT272-AX6 131.00
Are you assuming that the driveshaft was cut and balanced correctly?
I ask because I had a similar vibration and it turned out that the driveshaft shop welded the driveshaft off axis after they shortened it.
Suggestion: Pull the shaft and take it too a quality driveshaft shop and have it checked out.
After I got out of the Air Force, I worked in a brake shop for about a year. We would test drive the car and never bed the shoes/pads.
My Nissan dealership does our brakes. They don't bed the new pads.
Did you see these posts?
http://forums.hybridz.org/topic/118957-16-electric-fan-with-stock-shroud/ http://forums.hybridz.org/topic/108060-electric-fans/
Have you looked at Flex - A - Lite fans?
I am currently using a 3000 cfm fan and Arizona Z Car radiator to cool a SBC 350. Runs cool in traffic here in central Cal on 100 + deg days. The 3000 cfm is what made the difference.
https://www.flex-a-lite.com/electric-fans.html?cfm_range=10
http://forums.hybridz.org/topic/122990-arizona-z-cars-radiator/