DynaFlow Swap/better highway revs?

**60 LeSlobber** · 10-10-2007, 07:58 AM

Gentlemen,

I would love to hear any advice on getting better cruising speeds at lower RPM on the highway. I'm currently driving a stock '60 LeSabre with a stock 364 cid 2 Bbl Nailhead with stock DynaFlow tranny, torque tube, stock rear end, etc. I want to be able to drive the car for long distances and for many years in the future. I'm thinking that lower RPM on the highway would give me better gas mileage and longer engine life (duh?).

I've heard there are conversion kits (from Northwest Transmission?) or that a later model Buick tranny would fit my 364. I've also been told that any change in the tranny would require a total replacement of the drive shaft (from torque tube to open shaft) and that the rear end and rear suspension would have to be replaced/fabricated and would not be worth the trouble. I'm not ready to go Jay Leno and drop a 455 in it. I'm happy with the 364, if it just had "longer legs."

I stumbled on this site and am impressed by the knowledgeable postings I have read. Please respond if any of you have any workable ideas or horrible truths for me.

Thanks

**39CENT** · 10-10-2007, 11:50 AM

can only give you some ideas. a good one is go to google and enter 'Jyrki,s buick site' he built a 47 buick and has many good fotos and ideas that can apply to 55 buicks. The drive trains on 55,s are similar to 40 and up torq tube drives.

**telriv** · 10-10-2007, 02:40 PM

The DynaFlow tranny is a good cruiser. There are many things that come into play. The actual ratio of the rear gears. The tune of the engine & all of it's related components. As an example, I own a '61 LeSabre 4dr. hdtp. Also a 364 2bbl. but it is an A/C delete car. Meaning that one point in it's life it could be upgraded to A/C & have all the components nec. to complete the swap over. It comes stock with 10.25-1 compression. This alone adds more power & better fuel economy. I can consistently get 16-18MPG crusing at 60-70MPG, this of course depends on my right foot. This is after I have gone through all the nec. steps to make certain all systems were up to par. Then as part of the R&D on "My Rockers" I added them. Not only did it run better & smoother, but MPG went to 18-22@60-70MPH. You could also change the rear gears for a more favorable cruising RPM. Problem is you will have to source used gears as there are none available new.
Just some thoughts.

Tom T.

**60 LeSlobber** · 10-10-2007, 08:41 PM

Tom,
Thanks. I have heard about the rear end ratio change, but thought that would be risky with hard to find used gears and how it would slow down my off-the-line acceleration. My 364 is bone stock with a 2Bbl carb (Rochester?) except for dual exhaust with Flowmaster mufflers. I run regular gas with CD2 lead substitute in every tank, because I don't know the engine rebuild history and don't know if the engine has had hardened valves and seats installed. The car runs real well around local surface streets and I would hate to sacrifice low speed acceleration for high end cruising. My fantasy would be to find a workable solution, that feels like the dynaflow I've got - but with a third gear added on. The car gets up to 60 mph and I keep wishing it would just shift up another gear. Maybe I'm just programmed that way. Heck my tiny '68 Triumph Spitfire with a 1296 cc 90 hp 4-banger had a 4-speed manual with electronic overdrive and a top end over 125 mph.
This Buick's top end feels alot lower, and alot lower than other old Detroit iron I'ved owned - '52 '67 '68 '70 Cads, '67 Olds Cutlass, '57 T-Bird.

Richard

**sledhead** · 11-07-2007, 07:59 AM

Bendsteins in Minnesota makes a adaptor kit for later model trans. Kits run from $350 to $600 you could us a 700R4 which gives you an over drive. Yes you will need a drive shaft and rear axle change when you do this.