[steve25]

I went to Tin Indian site and they do not list the info for that grind unfortunately.

If we assume that it’s close to the original Cam then a 455 should idle 11% better then that Cam would in a 400 due to the 11% greater stroke of the 455.

I think there can be found a video of how a factory RA4 Cam idles in a stock RA4 motor, so you could at least listen to that.

Are you planing on running the 1.65 ratio rockers that would normally go with that Cam?

I guess you could also contact Tin Indian and get there opinion once they get back from Norwalk.

If nothing else your 12% bigger then a 400 motor should pull more idle vacuum.

I don’t know what your looking for in terms of a power band for your motor, but you can consider the hp numbers to be nosing over pretty well with a 455 motor by the time 5600 rpm comes around.

I would say that torque production would peak by 3800, so you should use that for setting up your converter if auto and rear gearing for your proformance needs.

Here a recommendation chart that HO racing use to publish on the subject.

To this day this chart is still very accurate in regards to a street / sometimes strip motor.

If your not planning on doing a lot of long distance highway driving, then do not disregard what the chart recommends for rear gearing if your running tall rear tires!