Dear Zeke;
The engine will be 800 RPM in neutral same as park & not 'racing', just 800. This may be above what the 'stock' 235 was, but well within (600 in drive) limits used by the V-8s.
Now; there may a difference in converters but It's all academic until you try yours on the road. It may "creep" a little, but It's the price you pay for the added horsepower to go on the freeway.
Happy trails.
