Not sure if this is the best spot for this thread but it seems like the most likely place.
So a few years back I swapped in a Goodwrench 350 to replace a terrible 305. According to Chevy the 350 was putting out around 280 HP and similar torque. Granted that is at the fly and at sea level I'm sure. From what I've read the power loss is roughly 3.2% for every 1000 feet in elevation, which is an absurd 20.8% for me. Even with those losses I think I should still see some power coming from the car, or more than I'm getting.
I have a car club that meets every weekend, and I have the title of biggest engine, oldest car, and slowest car, which hurts to have the last especially considering what else is faster than me. I am positive my transmission is a culprit here as its a 3 speed auto with a 3.23 rear and it is not built to withstand the 350 at all, but I could be wrong.
So what else could be stealing all the power? Please keep in mind my overall engine knowledge is pathetic, I have a basic understanding of how they work etc. but getting into the fine details I'm comparable with a monkey. I'll take all the advice I can here.

 

Your transmission is fine. Your rear is Ok too. Are you fuel injected or carb?

 

Idk about the transmission being fine haha, granted you haven't seen the bits of shaved gears I get in the pan either. I have probably 4-5 months till it fails based off what I see and most people I know all agree it isn't designed for the higher power motors. And I am running a rebuilt Rochester quad, a little rich for winter time but once I am positive it will stay warm outside it'll be running lean.

 

I didn't see you list what correction factor you use for drivetrain loss. I think I read it should be around 20% for an automatic RWD. What intake and exhaust did you use? If you used an LG4 intake, LG4 / LO3air cleaner, and LG4 / LO3 exhaust including manifolds, you're probably under 200 horses at the flywheel. If you went with the best aftermarket stuff you could be near 300. Now with a 20% loss to thin air, and another 20% loss to the drivetrain, you might expect 128-192 HP at the rear tires, if they are not slipping on the chassis dyno rollers.

 

What do you mean? The 200r 4 trans is what the buick grand nationals had. They can surely handle a 350 just fine. A 3.23 rear is a fine ratio

 

Sorry for any mix up there but this is not the 200r 4, I could only wish to have overdrive right now. I have the TH200c/ 200 metric. It's the 3 speed auto that I think was only used from 82-84 before the th350 became the main 3 speed auto ( based off what I have read about on here at least). The 200c or at least mine, has had a hard time with the new motor as I have already had it rebuilt a few months after the new motor was installed.

 

I don't know about the intake at all, except the 14" Spectre filter on the carb. I ditched the stock snorkel box soon after I got the car. I can try to find out more about the intake though.
The exhaust is the stock manifold for now with a 2.5" cat back system but I also have a 3" electric cutout that is before the cat and I have pretty much no back pressure (or hearing ) with that thing open.
128 sounds terrible compared to 280 haha, It amazes me how low that could drop from just a few factors.

 

I guess I should ask exactly what could I do to get some of my missing ponies. I would prefer to keep this cheaper for now, like a cam or heads etc vs. a supercharger.

 

Lets consider some of the other cars, say a 2400lb 4cylinder making what almost 200hp, now you wanna take a near 4000lb car with barely 280hp. Weight plays a big role, start removing items from your car to lose weight, like spare tire and jack back seats run minimal fuel level. Torque converter would help alot too, quick cheap horsepower nitrous.

 

I would love to remove the spare and jack but I have needed them on far too many occasions to part with them. I do want to install an aluminum drive shaft but that's only taking off like 10 lbs. running minimal fuel is hard for me to do as I have terrible gas mileage and it just drains out of this car when I'm not eyeballing the gauge constantly.