I will be doing the common 4.0L throttle body swap on my 2.5L YJ. I can get a spacer off ebay for $19, but its a 62mm. It has perfectly smooth walls, which is what I want. As far as I know the normal spacers are 60mm to match the 4.0L TB. I plan to bore out my intake manifold to match the spacer to provide the best gains in horsepower possible. Will haveing this bigger spacer cause any problems since I will be using a stock 4.0L TB, or will it be too big for the mod I'm doing? Will the velocity of the air going into the engine decrease since it has to occupy a larger space after passing through the throttle body? I know 2mm difference really isn't that big, but I don't want to mess anything up.

Thanks for your help