The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - How many rpms does a 454 like on the highway?

**THI** · 03-05-2023, 11:12 AM

Those RPM's are not really hard on the engine, just the fuel mileage! I have both a 1978 C20 Camper Special with 4.10's and TH400 and a 1979 C35 Dooley Camper Special with 4.10's & TH400 - both get around 10-10.5 MPG on the highway. I am considering replacing the TH400 on the 1978 with a 4L80E - the 1979 I am trading for body restoration on my 1975 Laguna Type S3!

03-05-2023, 11:12 AM	#3
THI Active Member Join Date: Jan 2017 Location: Traverse City, MI Posts: 171	Re: How many rpms does a 454 like on the highway? Those RPM's are not really hard on the engine, just the fuel mileage! I have both a 1978 C20 Camper Special with 4.10's and TH400 and a 1979 C35 Dooley Camper Special with 4.10's & TH400 - both get around 10-10.5 MPG on the highway. I am considering replacing the TH400 on the 1978 with a 4L80E - the 1979 I am trading for body restoration on my 1975 Laguna Type S3!