[Gator67]

Our faithful 68 Firebird 400 had some coolant seepage for a while, which I thought was from a leaky water pump gasket. I went to replace the gasket yesterday only to discover that the timing cover had deteriorated (see photo), so my little Saturday morning project snowballed somewhat. Anyways, trying to decide whether to go with another '68 8 bolt timing cover or a '69 and up 11 bolt. It's a numbers car and everything's mostly correct, and I'd like to keep it that way. However, we like to drive the car, but it does get a bit hot in the summer with the A/C on, and I've been told the 11 bolt pumps cool a bit better. Is it in fact true that the 11 bolt pump cools more effectively, and if so, how much of a difference is there?