The Holley and M1 2-bbl are decent mods, especially if youmay do so other mods in the future. I can also provide a precision machined TB for less money if you're interested.
For instance, I have this 52mm TB for sale. It is machined on a mill and lathe for precision that provides true and identical matching bores. It has a smooth taper bore with a radius at the top, the throttle shaft is milled on both sides for increased flow, it utilizes stainless steel button head throttle plate screws, and the butterfly plates are custom machined from T6061 aluminum.
I offer the modified OEM TB's as follows:
V6 (42-46mm): $174.95 + $30 core + $10 shipping US
V8 (50-52mm): $174.95 + $30 core + $10 shipping US
V8 (>52 – 53mm): $199.95 + $30 core + $10 shipping US
For this you get the machined and bored throttle body, custom 6061 throttle plates, milled throttle plate shaft, and stainless button head throttle plate screws.
You can ship me your throttle body for modifications or buy a unit outright plus the core charge. If you later send me your throttle body (identical to what you bought in good, usable, unmodified condition, and without damage) I will refund the core charge once I have received your core and am assured it is usable, unmodified, and without damage. I will check the condition right away and issue an immediate $30 refund if it fits the criteria mentioned above.
Once I receive your core, I anticipate up to 2 weeks for the completed unit ready for shipping but it may take less time. It is also subject to core availability so it is advisable to check with me first.