The car number plate was missing when I bought this MG and the DMV assigned a replacement tag which they installed on the door pillar. So I came here to MGE and the question comes up, what is the car number? DMV changed it. So where can I find the original number? In the MG forum a member posted an undocumented location for a chassis number stamp. The passenger side (this is LHD)frame rail aft of the motor mount bears a faint stamp of the car number. There is a reinforcement plate which wraps up around the chassis and bears the stamping at that location.
Strip the paint away, don't sand or wire wheel it clean as the stamping is not very deep.

I haven't found any simple options for a cold air intake with the Moss supercharger. I considered a hood scoop or louvers until this idea came about. The SU is against the firewall with little clearance for an intake tube. I've seen pictures of intake pipes routed behind the engine to the right front side through the radiator shroud OR the pedal box could be cut for clearance to the left side but I decided to try a more direct route.
Using the supplied air filter plate, a plenum was fabricated to deliver cold air through a 3.5" aluminum pipe and a K+N RF-1045 air filter mounted forward of the radiator shroud. The external profile dimensions of the old air filter were replicated forming a half cone, then a trapezoid shaped duct was attached with a 3.5" flange on the front side. The original air filter mounting cap is used to hold the assembly in place.
The idea was to use all the area possible between the choke and throttle cables and to clear the pedal box. The original cable mounting bracket is still used. The pedal box is not cut.
A notch was cut from a corner of the trapezoid duct to clear the wheel well and provide as much length as possible so the 3.5" pipe will clear the supercharger on the way through the radiator shroud.
The center of the cone was a bit tricky but it looks like it will be strong enough to hold to the original mounting bolt and cap nut. A new mounting bolt through the filter mounting plate serves to lock the assembly and prevent slipping. The intake pipes have 2 silicone hump couplings to allow for engine movement and vibration. Another radiator shroud was
purchased on Ebay to assuage any guilt about cutting into my classic MGB.
The clearance between the plenum and pedal box makes this installation a challenge but everything seems to fit. The K&N filter RF-1045 is an improvement over the original and the location forward of the radiator shroud sould opitmize supercharger efficiency. Next step is to fabricate a sheet metal partition between the filter and radiator to draw more cool air from the grille area. A Moss heat shield and possibly a header wrap or Jet Hot header coating will probably end up in the bay soon. I have installed Dynamat insulation over the pipe sections and plenum for added efficiency.
It's time to experiment with timing advance now that intake temperature is lower. Easy does it though...
Horsepower is not the primary concern in this endeavor as this basically stock three main will probably never have to respond to a wide open throttle. She's an old girl now and she deserves some respect. The main objective is to reduce the chance of detonation and the engine damage that it can cause. The effect is to save horsepower by maintaining a more dense air supply in extreme situations whether climbing hills or crawling around town in hot weather.
More pictures: http://www.64mgb.com/intake.htm

I got tired of waiting for Moss Motors to develop a supercharger package for the MK1 3-main MGB so I explored the options.
Moss says they have'nt produced a supercharger for for the 3-main engine because it has a unique water pump which would be too expensive to adapt to a serpentine pulley for such a limited production. However it is possible to install the (150-058) SC for the '65-'67 mgb with the suppled pump (and the provided serpentine pulley) with some modifications. The down side is that the engine block would need some minor grinding at the pump opening to make room for the newer style pump but it would improve cooling.
I chose not to modify the block. Instead, I had a water pump pulley turned at a machine shop to fit the original pump. The supplied pulley was welded to a billet aluminum fabrication.
The Moss supercharger kit supplies a serpentine generator pulley that sits 1/4" farther out than the original. Therefore, the machined water pump pulley height was reduced by 1/4" to line up with the idlers and serpentine crank pulley correctly. The pulleys lined up pretty well so our new water pump pulley turned out to be a good fit.
No real problems but admittedly no easy task getting this kit onto a 3 main MGB. The aftermarket header needed grinding at the head studs to clear the SC casting and there was some anxiety about the water pump pulley dimensions but it was all by the book after that. The new throttle cable has no provision to route securely behind the bonnet hinge so I used a lid switch (part#90016) harness clip from a Whirlpool direct drive washer. With minor alteration it clips the cable securely behind the hinge, preventing damage when the bonnet is raised.
After everything was installed it started quickly needing only timing, mixture and idle adjustments.

More at: /http://www.64mgb.com