What kind of budget are you talking and what torque numbers is the Big block putting down? The are not any economically friendly gearboxes out there that can handle more then 400 ft/lbs of torque. 400 ft/lbs is a pretty weak 454. With most Standard transmission the case itself is the weak point and they can not be made to be much stronger then stock.
GM used the Muncie M22 behind their big blocks but they are far from economical. These are the correct transmission for anyone building a SS clone so there are 3 buyers for every transmission out there. Even the M22 is only good to 500 ft/lbs.
There are some aftermarket option but they are not going to be cheap The tremec TKO-500/600 can range in price for $2000 to $2500. Keep in mind that is just the transmission you will still need the clutch and all the other parts.
The most common standards you see at swap meets are the T-5's and older saginaw's. Neither of those can hold up to a mid strength small block.
Last edited by Gorn; Today at 11:45 AM.