@sj86 45 specific forum is here:
Restoration and information for the FJ45LV and 45-series Land Cruiser
forum.ih8mud.com
Everything you could possibly want to know about disc brakes on a 40 series can be found here:
Tech Talk: Ultimate 40/55 Series Disc Brake Conversion Parts Thread (Work in Progress) - https://forum.ih8mud.com/threads/tech-talk-ultimate-40-55-series-disc-brake-conversion-parts-thread-work-in-progress.1039423/
The 2F if that is what’s under the hood(?) based on body indications is going to struggle to pull 37” tires and give you the driving experience I’d want (off-road, merging into traffic, etc.). You’ll also likely be in the 11-11.5 range on tire width. I don’t know of many 37” tire options below 11.5. Which as you well know means more mass of the tire and friction and will likely require a larger wheel size.
My suggestion is to drive the truck as is for a couple months and get a feel for it first and then make the upgrades you desire.
These trucks are old and slow in stock configuration. Sure…can they go faster…absolutely but it’ll require drivetrain upgrades. Think Toyota V-8/H55F or LS/NV-4500. Which then becomes a domino effect as you have to upgrade more drivetrain components to handle the additional HP and torque produced by the engine swap and don’t forget about braking for the new speeds the truck is now capable of reaching.
Mark
@65swb45
What rear gas tank are you using?