slugish sbc 350

I'm thinking it's the gearing. You could have 2.41 gears outback, it's going to be very sluggish in OD.

So what is the gear ratio you have now. The 3.73 gears will help your problem go away. For now just run it in 3rd gear if you want.

is your torque converter unlocking? do you have that hooked up?

i believe your problem is the gears i just swapped my 2.56 gears for a 3.73 monte carlo ss rear and man was it a big difference but nice build keep it going put some gear in it and youll never want to stop driving it like me

what kind of stall speed is the converter? I just upgraded from 2.14's or 2.41's to 3.73's not too long ago. other than that pretty similar. mild 350 and 700r4 and my rear was originally peg leg 7.5. I know this might sound odd but I actually like my dead gears better for higher top speed...on the parkways here in ny 75 is the new 55 lol. With 3.73's cruising at 70mph I'm right around 2300-2500 and don't like bringing rpms any higher for a constant cruise. With those gears if you were cruising at say 55-65mph and went wot trans should drop into 3rd and take off...otherwise in OD with converter locked it will be sluggish, almost sounds like chugging when accelerating moderately

That rear end definitely isn't helping you. Is your throttle cable adjusted properly?? - the car should downshift at highway speeds when you get on the gas. Also unsure of what HP crate motor you have but you are probably running under the RPM range of the cam along with a stock converter and large head runners it will be sluggish. Does the engine come to life around 3000 rpm???