Basically, I'll need more power than a factory X-head 340 as most of them couldn't get into 13's with 3.91's and I only have 2.94's. But, I'll need 318 2bbl mpg.
i do not agree the carb held back the 68 69 70 340 as well as traction
just a carb was 20 hp and the tunning tricks and a good short time is mid 13s with 3.91s
the 14.0 14.1 3.91 cars were traction limted with e70 tires but ran 99 mph
99 mph is mid 13s with a good 60
my 1968 gts 340 727 3.23sg all stock 85k miles with just spring clamps went 14.3@97 mph