4:56 or 4:88's Big Chevy ?

impstocker · 05-15-2014, 07:40 AM

Good Morning,
Started to prep my 12 bolt for installation but did not like the way the preload felt, so I will go through it. Now I have a chance to install the 4:56's instead of the 4:88's

I ran the 4:88's in my 68 Impala I/S car with the 396/325 combo. Going through the traps on a good run was 6600 RPM but this was a stick car.

I will be running the same 396/325 in my 65 Impala but with a Turbo 350. I expect to RPM higher now with the converter on the far end, would the 4:56's be better? I know when I come close to 7000 RPM with that motor it loses power. I also run 30" tires. Racing weight will be the same as the 68 Impala - heavy! 4095 lbs in I/SA

Any input would be appreciated!
Will Lamprecht - NED 65 Impala in progress I/SA

05-15-2014, 07:40 AM	#1
impstocker Member Join Date: Dec 2008 Location: Wingdale, NY Posts: 302 Likes: 27 Liked 53 Times in 16 Posts	4:56 or 4:88's Big Chevy ? Good Morning, Started to prep my 12 bolt for installation but did not like the way the preload felt, so I will go through it. Now I have a chance to install the 4:56's instead of the 4:88's I ran the 4:88's in my 68 Impala I/S car with the 396/325 combo. Going through the traps on a good run was 6600 RPM but this was a stick car. I will be running the same 396/325 in my 65 Impala but with a Turbo 350. I expect to RPM higher now with the converter on the far end, would the 4:56's be better? I know when I come close to 7000 RPM with that motor it loses power. I also run 30" tires. Racing weight will be the same as the 68 Impala - heavy! 4095 lbs in I/SA Any input would be appreciated! Will Lamprecht - NED 65 Impala in progress I/SA