These chrome T-stat housings are usually a universal fit for most GM vehicles that use this angle housing, on all the Mr Gasket ones I used they didnt say pontiac on the package but never had to elongate the bolt holes, they mount to a pontiac intake without any issues in my experience.
But, looking at summit, they have a Trans-Dapt brand that says its for pontiac V8, most others say for big/small block chevy...
https://www.summitracing.com/parts/trd-9230