Thanks for that info Startbartfast. For some reason the link won't open on my phone so I'll have to look when I'm at a PC - but sounds like what I was afraid of but didn't want to hear.
As for 302MGB, yes, I swapped the drivetrain in my MG to a 302/T5 combination from a Mustang and custom IRS using the short nose Nissan R200 differential (mine's from a JDM Skyline). You can see pics of my build here: http://www.britishv8.org/MG/RobFicalora.htm. BritishV8.org is a great board for British car engine swaps. And, we get together somewhere in the US every year. 2018 is Dayton OH in July. You/your dad should check it out. What model Triumph are you guys doing?