No template but this is what we did to cut the bonnet on our 70 RR to clear the tunnel ram. In a month or two will be building the carbon fibre bonnet using the mould pulled off the metal bonnet. Basically, with it off the car, I measured the distance on CL to the back side of the carbies from the cowl. I also ran a straight edge across the wings to get a height, after allowing for the camber in the bonnet. This could affect your clearance depending upon the height of linkage etc. Then measured to the front side of the carbies. Don't forget the air filters when measuring as they can overhang the carbies. More of an issue with a tunnel ram than a blower. With a blower you will also need to map out the blower drive pulley. Not hard to do, just measure once and cut twice.
The other thing to remember is the bonnet lift off or hinged? If hinged think about the arc it will pass through in terms of clearing the forward carb and filter.
For side to side just measure in from the edges of the wings. Not sure about A bodies but on a B body the engine is offset to the right. Remember this.
After making the measurements, lay it out on the bonnet and see if it makes sense. I used a Bosch jigsaw to cut it out. I first hole sawed the corners to create a radius as cracks love sharp inside corners. I managed to wear out the jigsaw blades I had so finished up the cut with a mini-grinder and cutoff wheels and then cleaned it all up with files of different profiles. Discovered the original bonnet was more rusted than I thought when a piece of reinforcement almost fell out when I made the cuts.
Anyway, once the engine and blower are in the car it is pretty much just careful measuring and remembering if you screw it up it is just metal.
Best, Dave
