I don't understand "why" the OP wants to remove the 90*, which uses a one quart filter and replace it with the straight filter system which uses a "smaller" filter. Plus, with the short filter it seems there is more heat soak from the exhaust system cooking the oil. Just my .02
No matter what the filter is near the exhaust whether it's screwed into the block or screwed into an adapter. Adapters tend to leak hence all the threads regarding them.