[scottj]

Just a note:
Do not confuse the 4150HP with the 4150, they're completely different carbs. The 4150HP has much better fuel metering. Whether it's used on the street or the track it will deliver fuel more precisely than the 4150 and as a result deliver crisper throttle response. For me the lack of a choke is a very small trade off.

Another note:
You can convert the 4160 to a 4150 with the metering block, but not to a 4150HP