Hey all. Short time lurker and newb here.

Two weeks ago, I spent 4 days wrenching on my 454 for a 4 day weekend trip...And another half day working on it at the camp site!

I would LOVE to drop a diesel (overdrive mandatory!) in it but I was also thinking about a SBC and overdrive tranny swap.

Right now, the powertrain is the 454 big block, a TH400 and 14 bolt corporate with :4.56 gears. Cruising speed is about 45mph. At 55, she's singin'. At 65, she's a screamin"!

The 454 is being over spun like 80% of the time.

The manifolds were cracked when I bought it so I replaced them with headers. I KNOW they're glowing at highway speed. I haven't melted any wires or caught on fire yet!

I have the timing advanced to the threshold of audible ping and the starter binds a little on start up. It does run cooler then it did but the temp still climbs while in the mountains.

I think my RV weighs about 7300 dry.

I thought about swapping out the rear for a :3.73.

I do have a 6BT in an old Econoline bus that ran through a Ford C6. (Very nice adapter kit) I could bolt that to an E4OD with the plate already on it.

I have a 6.9L Hino 6cyl bolted to an AT545 (no overdrive!)

I thought about finding a wrecked diesel G2500 or something, with the 6.5.

Since I don't have the time or money to do any of the engine swaps I really want, I was also thinking about a (4bbl headers and cam) 305 or 350 with a 4L60/80 through that :4.56 rear.

Is anyone running a ~8000Lb RV with a small block?

I had a K30 mason dump that weighed about 6800 and the 350 with headers moved it right along...power to spare. I hauled a 6 ton track hoe on a 9 ton trailer for two years with that truck.

I think the only time I would kick myself with the small block (if at all) is if I were towing a pickup truck.

I could buy a 2WD 1990 Silverado tomorrow for $500...OBO. Engine (supposedly) rebuilt 50k ago.

Anyone have any thoughts?

Don't worry about hurting my feelings ;-)

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Just pinning this onto my previous side note:

Driving my truck around for a couple days, I'm getting acquainted with it all over again. I drive it completely different now.

Looking at the new OD compared to the old one (ZF5 42 vs E4OD), the difference is, numerically, very small.

The auto had a .71 OD and my new 5 speed has a .77 OD.

The comparison via old but-o-meter, however, is profound.

That little 6/100ths of a rev makes an unbelievable difference!

Only one way to over come that problem and its about $1400.  A 2 speed gear vendor gear box right behind the trans or attched to the nose shaft of the rear axel. 

I talked to a guy about a low mileage, late 292 today. Supposedly runs like a Swiss watch.

Also, I discovered that the Gear Vendors / Doug Nash / Laycock overdrives are pretty much the J Type unit on the back of my Volvo M46 transmissions.
I happen to have a spare.

The Laycock to TH400 adapter is a MILLION dollars, so I'll be fabricating one, I guess.

The 292 came out of a dump truck that weighs more then my RV. Should be ok.
It's the same overdrive unit I have in my shop.
The Laycock J type is what the Gear Vendor unit is based on.

The adapter tube, I can make.
The shaft, not so much.




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