🚀 go-pugleaf

I once owned the same Mustang, '65, red, white interior, rag top.
I bought the car second hand and it had the BIG engine just
as you describe.  My first inkling that it was different was
when the guy at the Motor Vehicle Inspection Station ran it
up on a lift to check the suspension in the front.  It was
OK for the size engine.  I asked him what he was doing and
he replied that many of these Mustangs needed a heavier front
end in order to compensate for the bigger engine.  If the
front end had not been beefed up, he said he would have to
fail the car until it was fixed.  I can't help you with
what to use under there, but perhaps if you went over to a ford
dealer, they might have an old timer around who can help.
T. C. Wheeler