New LS6 Leaked: GM’s 6.7-Liter Gen 6 Small-Block
The next-gen GM small-block V8 is right around the corner, and there has been endless speculation on the details of the future of the famous American V8. Will it be DOHC or retain the cam-in-block 2-valve pushrod design like the current LT? What displacement will it be? Will it still be direct fuel injection? The guys over at Corvette Blogger have leaked some of this info on the Gen 6 small-block, and it looks like it will be in the form of a new LS6 V8.
Early speculation pointed to 5.7-liter and 6.6-liter variants that would be shared between the Corvette and several Chevrolet truck platforms. However, a leak from GM’s internal Parts Book suggests the next iteration may instead displace 6.7 liters for the 2027 model year. Historically, the GM Parts Book has proven to be a reliable source for uncovering future Corvette developments, and few references carry more weight than GM’s own parts division. This proprietary system catalogs every component a technician might need for diagnostics and repair, is restricted exclusively to GM service personnel, and is not publicly accessible online.
OHV or DOHC?
The leak shows some key details we’ll go over, the first of which is the OHV designation is the description. This stands for overhead valve, just like the LT, LS, and other small blocks that precede it. We had long speculated that the Gen 6 small-block was going to be a dual overhead cam (DOHC) design like the new Z06 and ZR1 models have, but redesigned for a more cost-friendly V8 that can be used in a variety of models like base model Corvettes and a version for the trucks, but it looks like our guesses were off base here. The new LS6 (that looks like it will debut in the upcoming Grand Sport model), is keeping an OHV design, helps keep costs down for manufacturing, so we aren’t surprised here and happy to see it.
DI and PFI?
The next leaked detail on the new LS6 is the DI and PFI abbreviations in the description. DI stands for direct injection, as the current Gen 5 LT uses. But PFI stands for port fuel injection, like the previous Gen 3 and Gen 4 LS engines used. So what’s going on here? Well, it looks like we’ve lucked out and GM has decided to use both! This may sound like it adds complications and costs, but this isn’t the first time this has been used in a performance application. The Gen 5 LT5 that was used in the C7 ZR1, and even the later Ford 5.0-liter Coyote engines, used this setup. This is good news for those of us who will be looking to modify these engines in the future and don’t want to be limited by the DI system at higher power levels.
Bring It On
We can’t wait to see what the new LS6 Gen 6 small block will be, but so far, we have some great details thanks to the team over at Corvette Blogger. Our guess? the 6.7 will be 409 cubic inches. A call back on the famous W-head big-blocks from the early 60’s with a 103.25mm bore (same as the current 6.2 and 6.6) with a 100mm stroke (3.937 inches). It would be cool if the 5.7 version of this new Gen 6 small-block was 348 cubic inches as well. GM should be releasing more information on the Gen 6 small block over the upcoming months (we were told early 2026 for more info), so stay tuned for more on the future of America’s next V8.
