Well if 6800 rpm is all you need then a cheap 68/69 307 or 327 Cast Crank will do and you can sell that Forging for Fair Buck to pay for the Machining and Gaskets and if your running Hydraulic Lifters you can't get much by 6500 rpm anyway.
But that OEM Forged Crank makes the difference between a 330 Hp/6500 rpm and an 425+ Hp/8000 rpm 327 taking consideration to: Static Compression, Cam, Valve Train.... etc and MONEY.
Nothing sounds like a 327 at 8G's - Not even a 302. I Road Race and you if heard my Down Shifts from 7g's, it's not the motor as much as the clutch staying together or sucking the throttle plates into the intake. It's almost impossible with a MK IV but I do it anyway.
My opinion is that you are pushing the limits of weight Vs volume metric pumps at anything over 460 cubes, for my Ride, and my heart belongs to the 327 (Aside form the Hi-Tech Engineering GM has today, the 327 offers the Most Rev's, the Most Hp per Cubic inch/Weight of any ENGINE GM ever produced for the Public at no Extra Cost ;o)
The demise of the Over Squared 327 being dismantled by GM is that it ran rich at idle and could not NOT pass the Smog EGR Devices imposed by USA Gov't STD's in 70. Canadian STD's where softer and the 327 in our Poncho with TH400's and 12 Bolts where sadly the LAST of the 327's with the "ASTRO FLOW" Decal on the Air Breather and the reason why ORIGINAL Beaumont's and Acadian's are sought after by enthusiasts (However CDN Poncho Sport Pkgs did come Optional 396 and 427 ASTRO-JET Decals in that Era which American's never saw).
Just a little RANT about 327 History and 291/292 Turbo-Flow's with the 68/69/70(CDN), Medium Journal Forged 4672 Crank (there is another # which escapes me and Mortec has become CRAP - This is L79 365 Hp Makings, whether you use the 2 or 4 Bolt 010 block replacement over the 2 bolt, if not for the purpose to mount as Vette Windage Tray and it was all Stock, Over the Counter, back in the Day, including a Holly Spread Bore 650 Dp 12R-5395B to fit the 6283751 Cast Rochester Quadrajet 4 BB Intake. Want to argue Please Do = 350Hp 2.02/1.6's 291's or NOT and if you want my Specs you had better Board me for a WEEK and I will show you how to add another 1000 rpm & 120 HP to the 327 with STK GM Parts (If you can find them today) After all the 70 350 LT1 was the most Powerful FT SBC Enigine built or was it a 68 L79 at 375 Hp - Did they Exist - My Dad had a Brown 68 4 Dr Sedan Strato Chief/TH400/3.31 12 Bolt Posi - NO the intake was not Alu and did not have the Flagged Alu Covers but it had a Forged Crank (which I still use today), Holley 650Dp/751 Intake, 1.94/1.55 291 Turbo Flow Heads with a 9.5:1 Static, 330 Hp, HFT CAM. HUMM! - What a car to drive as a TEEN - I switched him to Volvo's ;o)
Hey! Back in 74 nothing could touch the Volvo 140 or Toyota Crown. The Muscle ERA had ENDED. That Volvo and Toyota were indeed Very FAST.
You want Power, Revs, Dependability with a 4 Spd OD and 3.90 POSI - Just give me a 68 Volvo 123SS 2 Dr Coupe with a Dual SU B20 or that 74 with the Mechanical Lamba FI but them SOHC 6 Cly Toyota Crowns where AWESOME - The USA didn't contend with the Early Crowns like we Canadians had too.
