I think that all small block cars have the 90 adaptor. i have never owned a small block car though so I can only guess.
You can look to see if the filter comes right off the block or if it is turned towards the back of the car. If it turns to the back it has the adapator
'69 Road Runner 383 going to 440, 6brl hood, likely gonna race it
'70 Challenger R/T clone 440, 2nd owner, 300,00 miles on body, not kidding
'92 Cummins 1 ton, in need of restoration bad
'79 360 1 ton flatbed-for sale
'01 WS6 T/A- for sale