The limiter weren't installed in Mb back in 72.
More like a clogged fuel filter.
If the ignition is out after 1500 RPM then you may hear back fire as the unburnt gas leave the manifold it can ignite when contact the hot exhaust manifold.

OT my Eldorado had that happened once, cannot over 40MPH and hesitating, so we pulled out the mini fuel filter. But threading her back was a big prob, crossed many times. In the end we just took out the filter and glued the screw back in and added a bigger online filter.