We're in the middle of swapping out the 7-row 20002A oil cooler for a 13-row 20006A on the RV-8 and fabricating a framework around the baffle opening using 1/8" thick angle and 1/8" thick aluminum strips for reinforcement to prevent cracking. This may be overkill thickness, but the new oil cooler will weight almost a full pound more than the original one and I want it to be solid and durable. I've extended the inboard angle strip all the way up to the top of the rear baffle and will use a long bolt thru the entire thickness at the top, including a spacer across the "box" gap at the top, for attaching a cross-brace to go from that point on the rear baffle over to the engine case for extra support.
Your idea of making the bolt spacer tubes a wee bit shorter to incorporate washers on the insides of the oil cooler flanges to spread the load there sounds like a very good one, I think I'll do that too while I've got everything apart.
And yep, we know the 13-row cooler is a bit too wide for a baffle mount and two or three rows will be covered up, but it'll still leave 10 or 11 rows open to airflow which should be a big help towards reducing the oil temps over the little 7-row cooler, and we already have the 13-row cooler on hand, otherwise we probably would've bought the SW 10599 cooler instead.
