1972 Build thread.

[hemi43]

Originally Posted by Spf79

I am glad to hear that about the 4:11's, I almost went 3:73's so I could save money by not buying a new carrier for the front end. Everyone I talked to said 4:11's, so I let them twist my arm into a tru-trac locker for the front lol. I don't think I will get jack poop for mileage. Going old school 383 with a built th350 behind it... shooting for 9 m/g! Yes!!!

That is funny about them coming from the same manufacturing company. Thanks for the info, I just ran into this with Timken bearings and SKF seals being the same manufacturer. Seems like a waste of money from the marketing standpoint? At this point as long as I don't screw up the install and they don't go bang in the next ten years I will be satisfied.

Back to the 4:11's with 35's, how are you at 70mph? What is your RPMS?

Why did you have to buy a new carrier for the front? 4.11's are available in a "thick" version that would bolt right in.
At 70 MPH I'm around 2100 RPM, but don't forget I have a 4L60E which has a 30% overdrive. I get a true 25 MPG (imperial) with my Blazer, and that's one of the reasons I used the 5.3
You won't screw up the gear install ! If you have a nice contact patch and the proper preload it will be perfect. Just take your time.:-)
BTW, I really like the item you used for reference to show the thickness of the header flange. That was very Canadian of you !!