You should check it with an aftermarket tach to see what the engine is really doing. 3rd gen Camaros are notorious for having mis-reading tachs. Do a little online searching, you'll find a lot of info about it. Mine in the 91 read an easy double of what was true. Replacing the tach didn't fix my problem either, which I'm figuring was because the used replacement tach was bad too. For 82-89 models, the likely culprit is a bad capacitor that is located on the back side of the tachometer face. And with the 90-92 models would be a bad printed circuit board behind the tach in the cluster. More than likely, your tach is just "lying" to you.

 

Yes, that 4:69 gear ratio would explain everything....Good luck, it sounds like it is a strong running 305 grocery getter Frankencar with a lot of mods.

 

ya, i was thinking the tach might be reading wrong, i'll look into an aftermarket tach. i'm also looking into white-faced replacement guages instead of the black maybe. idk, the tach now has really bad lighting, so we'll see. it also builds revs quickly and acts weird overall, so i'll just have to see what the deal is, if its wrong, its wrong by ~1000-2000RPM off depending on speed. thanks again for the advice/help! btw the former owner said the rearend ratio should be factory!, yay! We also embarrased a guy from school in his Civic on the highway today, about 3/4 throttle and we left him in the dust! lol so much fun!