I'm at that point (Head job vs New Motor)

here are the latest numbers, all ports are within a few cfm through out the lift 'minus one port where the core shift was horrendous', yet it still flows close 'within 7 cfm'. The highest int flow of the bunch does 205cfm, the lowest of the bunch does 201cfm

INT/EXH PORT NO.6
----int--------exh
.100-61------na
.200-128-----94
.300-174-----114
.400-196-----133
.450-204-----148
.500-199-----153
.550-200
.600-204
fwiw comparison/how close the numbers r.
No.2 INT----No.4 INT
.100--59-------58
.200-122------125
.300-175------171
.400-199------198
.450-202------205
.500-199------200
.550-201------200
.600-203------205
I ported to get as high a low lift number as i could 'given stock valves and basic 3 angle' without bringing it to the point of no return. The cam is a .470 lift 262* solid now...so it along with these heads will work really well and make a drastic improvement in power for this lil 273.
My advice to u all is when working with the early heads '273' look the them over really good for core shift, it was so bad in one port that the guide had about .050 on one side and 3/8 on the other along with the straight side bowl which is usually proud into the bowl..was actually inverted ...

If the bore would allow, we could further...and even find more flow with nothing but the same work done.

but all in all, not bad for a port that flowed 172 cfm peak to start..