You can use shorty's from a 67 Camaro up to a 92 Camaro and everything in between...(well almost)
Basically, Monte Carlo,Regal,Cutlass,Grand Prix from late 70's to early 80's were the same, also Malibu,Camaro, and some truck headers will fit.
I had a 83 Malibu wagon that had a healthy rebuilt SBC in it and I used headers that were for a 67 Camaro. They were the "big tube" shorty's. If the car has been lowered a decent amount you will want to go with a short tube header for clearance reasons.Like these
If its not lowered and you are not planning on it then I would go with a full length header for more low-end power . If you are talking about a 'block hugger' header like these
You can kiss that idea goodbye...the header will dump straight down into the A-Arm Crossmember.
If you still need any help let me know, I ran a parts store for awhile...you tend to pick up what will ACTUALLY work and what the books say will work.
Later,
WEIMER