This is a fairly open ended question:

Full race A-Series vary from 100 hp for A12 to 150 hp for A15, keep in mined these are motors revving to 9K with 14-1 compression. In streetable trim I would expect 75 to 100 hp depending on displacement.

As a comparison my A12 with GX cam, GX head with ports clean up and 39 mm flat slide carbs made 73 who and it would be streetable .

For an A13 with GX cam, GX head with ports cleaned up and 37/30 mm valve and flat sled or weber carbs my guess woul be about 85 hp at the wheels.

Tom