Suspension Options?

The T-bar suspension, was cutting edge at it's introduction. Nearly 60 years later it is still being copied.

Fitting headers may not be a bolt-in deal, but most 273s don't need long-tube headers anyway . It takes a pretty big cam in a 273 to really need long-tubes.
If I had a first-gen barracuda V8 and thought it needed long-tubes, I would fabricate them before I would swap away the T-bar suspension.Or I would pay someone to make the popular brand ones fit. I mean prices for those aftermarket set-ups, after all is said and done
are way out of my budget.
In Canuck bucks, they are about equivalent to 670 hours of wages to me.To me, that represents a half a year's wages.
I don't know how many sets of hand-made headers I could fabricate in 670 hours, but I bet it would be more than 1.

Yep, T-bars have a lot of good attributes--low center of gravity and simplicity being two important ones. Bad points include space intrusion and lack of spring rate adjustment without changing out the bars. My boat trailer has t-bar suspension, and it rides like a dream. If you have the talent to fabricate the headers, AND if you select primary tube size and length, collector configuration, and secondary size and length properly, you can certainly achieve better scavenging than 99% of the manufactured headers out there. Unfortunately, with my skill set, it would probably take me more than 670 hours to do it right!