I have a fairly beefy 350 SBC bored +.060 (360, I think) and for most people it's about right. For others it's too much. It's not enough for me so I'm building a strong 400 SBC. It just depends on how much TQ/HP you want. To each his own. FWIW, this current setup will run high 12's all day. I expect to get into the mid-low 10's with the 400 and other updates. A strong 355 matched with the right transmissoin setup, torque conv., diff. ratio, tires etc. can easily get you into the 11's but it's easier and more streetable with more CID. A 383 can be made a little more street friendly ET for ET than a 355.