Difference between AQ271 and AQ311

[LegacyT]

Both are GM 350's except the 271 makes 275 hp @ 4600 rpm and 311 makes 307 hp @ 5200 rpms. Whats the difference that makes more power? Is it the higher redline for the 311? is it built and carbed any differently?

 

[Don S]

Re: Difference between AQ271 and AQ311

311 is rated for 4600 to 5200 WOT rpm. 271 is 4200 to 4600. So yes, the HP is coming mostly from the higher rpm.
Some things I found different by looking at the service manual specs.
311 has 4 bolt main bearings, 271 is 2 bolt.
Cam has higher lift on 311
Timing 2? different, carbs the same.
Everything else seems to be the same.

 

[LegacyT]

Re: Difference between AQ271 and AQ311

Thanks for the info! Another qestion... Why did it only come in SP?

 

[Don S]

Re: Difference between AQ271 and AQ311

They did come with the DP as well as the SP... Both the 271 and the 311