Perhaps sp means special production. I inherited the 69 coup just weeks ago and I am learning on the fly how to understand the vin and cowl tags. This site is full of documented and accurate info. Great site. Also, do I call her, the 69coup, a Tempest or a Lemans?
Welcome to the forum! The Sport Coupe designation was used by Pontiac for 2 door A-body Post cars from '64-69. The Sport Coupe designation had even been used even earlier, on big cars & on 'the 63 LeMans (Y-body). To verify what '69 A body Sport Coupe you own, ck the first 3 digits of the cars VIN. For '69 models, 233 series is the Tempest, 235 series is the Custom S, & the 237 series is the LeMans. All three trim series, one could order a "Sport Coupe", with same drivetrain no other option examples of the '69 3327 Tempest Sport Coupe weighing 60 lbs less than same base equipped 3727 LeMans Sport Coupe.
For the 1970 model, Chevrolet dropped their 2 door Post model Chevelle. Pontiac, however, retained the 2 door post A-body body style, but dropped the Sport part of Sport Coupe bodystyle name, & just referred to its 2 door post model A-bodys as Coupes. Many years ago, a long time collector & near 3 decade Pontiac dealer explained to me it was too confusing to have a '70 LeMans Sport Sport Coupe ('70 model 3727 body style), so the Sport was dropped on Sport Coupe bodystyle name.
The '70 model 3727 LeMans Sport Coupe ended up not being very popular, so for '71 model, one could only get the 2 door post A-body style from Pontiac either as the basic T-37 Coupe (3327) or the LeMans Coupe (3527). Originally, the '73 model A-bodys were to be introduced as the new for '72 models. Several factors, including the prolonged Fall of '70 UAW Strike delayed the newly designed bodystyle, as a result, there ended up being an impromptu '72 model Pontiac A-body lineup. For the '72 models, the 33 series was dropped & the base bench seat LeMans 2D27 & 2D37 bodystyles received a near identical interior from that of same body style '71 T-37's (71 233 series). In order to get the more frilly & heavier upscale interior on a '72 LeMans 2 door hardtop or convertible, one had to order the LeMans Sport option. The LeMans Sport option was the only way one could get bucket seats or the heavy Strato bench seat bench in a 2D series 72 LeMans, & this upscale interior & trim option was not avail on the '72 LeMans Coupe (2D27 bodystyle).