65 mph in a 3600 might be a little fast - wait to hear from someone who has a 3600 with a
4:47 or 5:14 rear end.
The Hydra-Matic is uncommon and it is supposedly a sturdy transmission.
The 261 was supposedly not a factory option on a 3600 but just about anything might have been arranged on a special order. Casting numbers would allow an identification of the year of the engine.
