Higher speed rear end

[Phil]

I have a stock 1938 Packard 8 cyl coupe. Right now I'm sort of limited to about a 45 mph cruising speed because it has a 4.36 ratio rear end and I'm pushing 3000 RPM at that speed. I'm wanting to drop down to a 3.3x-3.4x ratio in order to do short highway hops. My current rear end is a 5 on 5 bolt circle and measures 61 7/8 " from the brake drum bolt faces. I've heard that some Camaro units fit quite well. Can anybody give me a year/style of such a unit?

[terry russell]

Re: Higher speed rear end

I think the 2bd. gen is the one you want.
terry

[jays67]

Re: Higher speed rear end

wth out messureing mine i would say ya second gen i can chevk both i have a 68 and a 73
the 2 gen ones ran from 70 to 81
also look into s 10 rear ends

[CTX-SLPR]

Re: Higher speed rear end

If you want to keep the 5x5in bolt pattern you'll need to be looking at full sized GM and trucks as well as some 70's full sized Fords. Probably the best bet is an 8.5in 10-bolt out of a 78-80 Seville if the 2nd Gen F-body stuff is good, its basically the same axle with the 5x5in pattern. After that its full sized car or 2wd trucks, cars will have coil springs though.

[Mr4Speed]

Re: Higher speed rear end

Astro vans are 5" bolt circle too, and most have 3.42 gears.

[Loren]

Re: Higher speed rear end

Be careful with the GM 5/5...for example, only the 4-wheel disc-equipped Sevilles had a 5" circle, the disc/drum cars were 4 3/4. Full-size GM and Ford cars may be 5" but will usually be too wide. All these cars will have 2.73-3.08 gears, maybe not what you want. S-10s too narrow, don't know about vans...I'd find a shop that did rear ends and ask their advice for the easiest swap. Of coarse nothing is going to be a bolt-in.

[jays67]

Re: Higher speed rear end

round body caprices and caprice wagons were 5/5 with drum breaks
i had a 92 caprice 305 car with 5 on 5 wheels had the cop wheels after i got done and truck wheels from a 92 chevy truck with my snows on it for winter

[HoosierGTA]

Re: Higher speed rear end

Astro vans are 5" bolt circle too, and most have 3.42 gears.

Astro vans have a shorter axle on one side than the other. Right side is the short one.