These are a Berg casting that we machine to 58mm. The industry standard 48IDA bolt pattern and dimensions are maintained so they fit all 48IDA manifolds without modification or adapters including V8 applications. Installs facing the same as the Weber 48 IDA so no new linkage needs to be made except with carb to carb linkage such as Tayco, you also need to purchase GB 460J mounting brackets. Idle and progression circuitry is properly designed for the larger bore size, which provides easy tuning, and smooth acceleration from idle up. Topped off with a 62mm velocity stack which provides far more flow, yet still fits our GB 505-51 velocity stack covers. Designed for what is required with today's larger heads with 48mm intake or larger. These feature sealed ball bearings with shafts made of 12L14 steel.
This provides proper seal at the shaft and maximum longevity. Other companies carbs with bushed, non-bushed and needle bearing shafts often leak vacuum at idle or low speed causing rough idle and are often hard to jet. The velocity stack is billet 6061-T6 aluminum. Dual gas inlets provide your choice of the stock Weber 12X15 banjo bolt location or 3/8" pipe on the top of the carb top. Plugs are furnished for both locations, again your possibilities are either using the standard Weber banjo and bolt, or a 3/8" pipe fitting to AN-6, or AN-8 for aircraft lines. The 52mm flows 340cfm per throat, the 58,, flows 500cfm.
SW 12# for a single carb, SW 24# for two