BBC 427 or LSX LS7....

[LS6 Tommy]

Why does everyone keep saying that the big block will make more torque? If they have same displacement and can accommodate the same cylinder pressures, they should be capable of equivalent torque. Heck, it has 475 ft-lbs STOCK and lingenfelter gets them to a reliable 575. Plus, you'd never have to worry about cold or off-idle stumble with EFI. I understand the look and aura arguments, and they do have validity, but from a performance standpoint, what am I missing?

They may have equivalent torque peaks, but they make them at different places on the curve. The LS7 has a bigger stroke and a smaller bore than the Mark IV 427. You can spin the daylights out of a good Mark IV, plus that new ZL1 block has a lot of room to bore. The LS7 may make more torque at a lower rpm for street manners, but GM says 7000 rpm is the max you should turn it. At least a stocker. The Mark IV will really pull on the top. Depending on what cam, heads & bottom end he uses, he can see and easy 8000 rpm. IMO, the Mark IV has more potential in this situation just because I think he may make more power for the same or less money unless he put a power adder on the LS7.

Tommy

[Yenko boy]

I really appreciate all of the help guys. I have decided to keep the BBC 427 and put a big single on it to make it a bit more unique.

[badazz81z28]

I really appreciate all of the help guys. I have decided to keep the BBC 427 and put a big single on it to make it a bit more unique.

So what came of this?

[MAGONSTERZ68]

I’m a fan of big inch LSX power plants just because of the advantage of newer tech and design.