Recently aquired an 87 Z-28. Not sure what size engine it has though. 8th digit of the vin is F which makes me think its a 305. But then I ran the vin and rpo codes and it said it was a 305 HO. Could it be? I didnt even know they made 305 tpi HO's. And then under the hood, on the far left sticker it says 5.0 Liter and then right under that it says 5.7 Liter

GM stopped putting 305 HO engines in Camaros and Firebirds in 1986. These have always been carbed engines.

Your 87, if it is a TPI, probably puts out more hp than an HO anyway. HOs topped out at 190 hp while some of the 305 TPIs hit 225 hp.

Your 5.0 Litre and 5.7 Litre stickers are apparently part of someone's "upgrading" efforts and should be ignored.

Vin "F" is the LB9 motor or the 305 TPI engine. 195HP and 285lbs/ft.

Recently aquired an 87 Z-28. Not sure what size engine it has though. 8th digit of the vin is F which makes me think its a 305.

Here are the official published specs for the 1987 305 TPI (VIN engine code F):

With auto: 190 hp @ 4,000 / 295 ft/lbs @ 3,200 ("peanut" cam)
With 5-spd: 215 hp @ 4,400 / 295 ft/lbs @ 3,200 (better cam)


But then I ran the vin and rpo codes and it said it was a 305 HO. Could it be?

Some databases list the 305 TPI has an "H.O." Officially, this terminology was never used with this engine.


on the far left sticker it says 5.0 Liter and then right under that it says 5.7 Liter

Somebody's been messing around.... The first thing I'd check is the VIN label on the hood. Is it original to the car? If it is, the 5.7 sticker was added. If it isn't, then who knows for sure....

Alright, I will get a check the vin on the hood and take a pic of that sticker.