I have cummins 6bta5.9 330 turbo diesels. I had to remove the exhaust elbow for repairs in order to remove the bolts from the flange had to remove the after cooler now am unable to locate gaskets for the after cooler. Any advice
Welcome aboard! I'm a tad confused with your post regarding removing the aftercooler if you needed to get the exhausts elbow off. The exhaust elbow/flange attaches to the turbo exhaust neck with 4 bolts. I have had problems getting the bolts out to let the elbow off the turbo, resulting in the turbo removal, but the aftercooler can stay in place. Also the only "gaskets" on the aftercooler are both sides of the heater element in the air path before the inlet manifold. There are O rings top and bottom in the aftercooler caps, but they could have stayed on if you were removing the aftercooler.
If it's the heater element gaskets you're after, to get you out of trouble, I've cut gaskets from gasket paper that would suffice since it's largely air passing thru. I'm not sure where you're located, but for most Cummins parts etc including the aftercooler O rings, Sbmar.com is one excellent source. If you are new to Cummins engines, their website is a wealth of information - read thru Tony's Tips for just about everything you need to know.
Also if you can complete your profile with location info etc, that will help other to help you. Have fun putting things back together.