What is the best size throttle body?

[bsedwebt70-5.0]

I have a basically stock 1993 5.0 Gt 5spd with 1.7 motorsport roller rockers, underdrives, no smog - cats, pump, thermactor stuff, cannister purge stuff, etc... and want the BEST low end torque and power from idle to 5k rpm. Should I stick with the stock 55mm unit or what? If I change it do I need a larger mass air meter? Do I need to change the plate behind it with the coolant tubes too? By the way - what size are these coolant tubes if I do remove it I will need to replace the rubber hoses to be safe. AND how do you keep coolant from leaking out - if it does how do you get the air out of the system with the bubble that will form in these small tubes? I would hate to chase an air bubble afterwards and even if I just loosen the throttle body I get coolant oozing out of the gasket.. any ideas?

 

[luckythirteen13]

if its stock, 65mm is plenty big although with the stock maf you will notice little to no gain with a bigger tb. the stock maf is about 50mm so no matter how big of a tb you get, it will never flow more then the maf. yes you will need a new egr (the thing behind the tb) and no you wont have to replace those rubber lines