Found this on http://racingbeat.com

Thought it might prove valuable here.

http://racingbeat.com/PDF/intakeguide.pdf

The following chart lists the approximate possible peak horsepower output of various intake systems offered by
Racing Beat. These output valves assume that a header and an open or performance exhaust is being used for each application. Since stock horsepower output varied from model year to model year, the values listed are approximateand
reasonable estimates for each engine/intake application, your actual output may vary.

.......................Weber Weber Holley Holley Holley
Engine Porting 48 IDA 51 IDA 465 600 650
12A
Non-Ported .........NR...... NR.. 155 NR NR
Street Port......... 165...... NR.. 165 NR NR
Bridge Port......... 230...... NR.... NR 250 NR
J-Bridge Port...... 240...... NR.... NR. 260 NR
Peripheral Port.. 270..... 280.... NA NA NA
Peak Horsepower Output (HP)

13B 4-Port
Non-Ported....... NR....... NR ...165 .NR NR
Street Port......... 185...... NR... NR .195 NR
Bridge Port NR.... 255..... NR.... NR 255
J-Bridge Port NR.. 265 .....NR.... NR 265
Peripheral Port NR.300....NA..... NA NA

13B 6-Port
Non-Ported....... NA...... NA ......NR.. 180 NR

NR = Not Recommended
NA = Not Available

 

pretty cool

 

What is the stock HP for a carbureted FB?

 

101 for the 12a.

 

Seen it, posted it .

~T.J.

 

What would the output be around with a streetported 12a? Nikki carb and exhaust...