Please help me find my lost low-end torque!

304V8 '77 CJ-7 mostly stock. I just fixed my exhaust, where the the manifold attaches to the exhaust pipe and also fixed a hole in the back of the intake manifold. This has pretty much closed up most of the exhaust leaks and quieted the engine. But now it seems like my low-end torque is nil. It's not nearly as quick off the line or going up any grade. Any ideas on this? Is it that the exhaust is more restricted w/out the leaks? Please help me trouble shoot this as it gets old slowing down traffic over the bridge on my way home. Thanks.
rich
77cj7304QtracTH400

fratt