[JEC3039]

Need some Forum advice regarding transmission conversions.

Planning a RAII / Turbo 400 clone build in a '68 Firebird. Been looking for a needs nothing/little roller for awhile but having no luck, so now looking at complete cars. Have 2 candidates. One is a manual 4-speed car and the other is a 2-speed automatic car. Both have interior consoles.

Which is more favorable to switch to a Turbo 400 setup?

[Trevor78]

One is a manual, one is an auto.

[tom s]

Auto to auto is always more EZ.Tom

[Vroom_vroom]

Why a power glide? A two speed would get old real quick.


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[JEC3039]

Vroom-vroom: the Powerglide wouldn't stay in the purchased car, it would be replaced with a Turbo 400. The question is is that easier to do than a 4-speed manual to Turbo 400 swap?

[tom s]

The auto car will have the right console already in it,the 4speed car will be more labor to remove all the linkage,Xtra pedal and get a auto console for it.As I said,auto to auto more EZ.Tom

[b-man]

Use the automatic car.

The main thing needed will be a TH400 transmission crossmember as well as a TH400 output yoke and shortening the driveshaft about an inch.

The manual trans car has the wrong console and the wrong crossmember as well not to mention the wrong pedals.

I’d base my decision upon which car is in better condition body and interior wise and in the colors you prefer, the transmission it came with isn’t all that important really. You might not even want a console in it so that might not affect your decision either.

[Goatracer1]

If you pick the AT car you get correct console(but wrong shifter). cooling lines, flex plate and cooler in radiator. If you buy the 4 speed you can sell the four speed set up to off set expenses. Most likely nobody will want the 2 speed auto.

[JEC3039]

Tom / b-man / GR1:

Appreciate the strong leaning toward the auto car.

Believe it or not, the two cars (one in Indiana, the other in Virginia) are the same color, so that's a wash, and both appear to be in similar condition.

I actually had good luck selling a p'glide & convertor from a '66 GTO at the Ames/Norwalk event several years ago, so maybe that magic can repeat.

Thanks

[Charlie Brengun]

If you're considering swapping something to a th400.. As you're going through the motions of swapping a trans anyway, might aswell have a look at a 4l80e instead.

[Trevor78]

x2 auto or manual, I'd be adding an overdrive. May not suit your plans.

[Half-Inch Stud]

Overdrive...manual shifted 4L80 prefers both column-shift and a Hurst Comp Plus on the tailcup bolts and 4-speed hump.

TH400 for the reliability and full range of uses except limited highway joy without OD.
Either car will do; go for condition, and maybe the rear gear that are most highway ratio'd. Auto console setup car is advantage for your ask.

[grandam1979]

We have converted 68 firebirds both ways if you use the stick car as said you will need to replace front carpet and remove stick hump from floor then pedals. You will also need the neutral safety switch wiring to run to shifter. PM me if you want we have 400 yoke driveshafts and lots of parts if you use the stick car we have a console and shifter available also. Best of luck with the car.

[hobbygto65]

How do you adapt a 4180E to Pontiac motor?

[grivera]

Originally Posted by hobbygto65

How do you adapt a 4180E to Pontiac motor?

http://forums.maxperformanceinc.com/...d.php?t=858568

https://www.jegs.com/i/JEGS/555/6017...8aAnsPEALw_wcB

[JLMounce]

Just need an adapter for the 4l80e. Find an early 4l80 with the cooling ports at the front of the trans. You can use 90 degree banjo fittings and not have to do any tunnel work.

If you can find a 2wd model with the bolt on yoke, you just need a counter bored yoke to use a slip yoke.

I chose the US Shift quick 4 for the controller. A stock 4l80e would be all you’d need behind a stockish 400. I’d even use the OEM torque converter in that application.

[tom s]

Why not a 200R?Tom

[Half-Inch Stud]

Originally Posted by hobbygto65

How do you adapt a 4180E to Pontiac motor?

$56 adapter plate from JEGS.

[b-man]

Or just keep with the original theme of a clone RAII automatic car and run the tried and true TH400.

Simple, easy and inexpensive.

[JEC3039]

I appreciate all the replies and the logic of an overdrive. I should have said up front the car, though streetable, will be used at the Pure Stock Muscle Car Drag event here in Michigan which is held each fall and per the rules it can only be a TH400. So for now, that's the limit.