Yup the 8007 sounds good.
Ok the 51.2 jet is a #51 jet, the extra 2 means "close tolerance".
The 25 is on the accel pump shooter. It controls the RATE that the accel pump shot goes into the carb. I think mine is also a 25, works good.
The secondary jetting is controlled by the number stamped on the plate with the funny screws (actually a phillips works pretty good on those). Should be a #34 or #59 plate which has .052 holes for "jets". From there its a bit complicated, but it seems your 8007 should be a tad richer than my 6390. Probably jetted just about right if you also run headers.
The jets wont come in any of the Holley rebuild kits, you have to get those small ones pair at a time.
I'd get a pair of #48 and a pair of #54 jets.
Try the #54 first (safer to go richer), use a Gtech or dragstrip or even a stopwatch or butt-meter. If its faster, leave em in. If not, use the #51s. If its slower, try the #48s, etc.
You can also try different springs in the vac secondary tho watch out, its easy to tear that $10 diagphragm. Make sure it WORKS if you fiddle with it. I clip a paper clip to the vacuum rod, up high against the housing, then go out and floor it,
then see how far down the rod the paper clip got moved. That tells you how far the secondary was opening.
Beyond that and setting the floats, if its a new Holley I wouldnt mess with it much.
Check out the Holley website too. I havent bought a Holley book in over 20 years so not sure which is the best one now.
