The problem with bending SS exhaust tubing to anything near 90* will collapse the tubing. You may want to look into 316 sanitary tubing. You can buy this tubing in 15*,30*, 45* and 90 degree sections and with the size needed (1 1/4 to 1 1/2") to build any configuration needed.
It will never rust, never split and be impervious to any chemicals used in the cooling system. It will also be lighter in weight than ss exhaust tubing. This stuff will also polish to a chrome like shine.
Build looks great. If only I could get started on my conv.
Mickey