Build Thread 1978 Mercury Cyclone. The pig is in the pen.

There is input, and there is “ input”.
When I as for opinion, and somebody tells me that i should dump the entire combo, and put a coyote in the car, or has any tinge of “ I told you so”,......silence is the better reply option from me. I realize that alot of that is in jest, but anybody who has read what kind of struggle this has been to get this thing running, and running good enough to be happy with it should know that i’m at a point of fed up with this engine choice already. I’m not in a position to take a beating on this and bail, especially given the fact that the engine .......runs.

There are 12 of you guys that look in on this thread, and when I ask for advice that’s what i’m looking for.
so,...here is my official cyber phone call...( i’m dialing you all up right now) @a91what,

@TOOLOW91 ,@General karthief ,@RaggedGT,@95BlueStallion, @HotFox, @74stang2togo, @Hoytster, @LILCBRA, @KZGUNS,@Olivethefet, @dr. Dan W. @Noobz347@

Im asking for Your advice/opinion...

As i’ve said, You don’t have to know dick about a toyota to have an opinion. The three options boil down to a simple choice.

A. You attempt to fix what you have, hoping that maybe modifying the converter mounting depth into the crank will stabilize the converter better. That’ll require a new flexplate, and a rebuild on the converter. The anticipated cost for this is about 300-500 bucks. The upside is that this trans fits, works, and will tolerate the power and of course, the cost. The downside is that you do not know if that will be the fix.

B. You modify the A 340. It can be made to handle my HP goals. To do that will require a new converter, a total rebuild, upgraded internal parts, a shift kit, a trans controller, and a two piece drive shaft. the rear trans mount will have to be modified. It will cost at least 3 grand to do. It is a complete rebuild, with machining required to upgrade the internals.
The upside is that it will fit, it is what came behind the engine from the factory, so there won’t be any side effect vibration. The downside is the cost, the complexity of the fix, the fact that there’ll now be a 2 piece drive shaft in place of the one that’s there. I’ll have a mindless auto transmission controller controlling the trans from ”D”, or i’ll have to devise some paddle/button shifter as mine will probably not work.

C. You buy the 800.00 adapter that allows a 4l80e to fit. You’ll have to buy a 4l80e used for 600-800 bucks, and hope it’s not a basket case...It will probably have at least 100k miles on it. You add the 300.00 Transgo valve body modification kit that allows the same manual control of the trans that you have right now. You add a 600.00 converter. You‘ll have to change the trans mount, and shorten the drive shaft.
The upside is that once adapted, there should be no side effect vibration. There are numerous adapters made for this combo. If the trans is healthy, it is virtually indestructible. At my 600whp hp target, the trans will tolerate that power all day long. Despite the fact that it is a different trans than the engine, it’s actually easier to make it work than the factory trans.
The downside is that It might not fit. A 4l80e is gigantic. It’s also heavy as hell weighing nearly 300lbs. The adapter is 1/2” thick, and there isn’t any room behind the engine to accommodate that added thickness. Going this route may force a redo of the engine mounts to allow for that, which will force a redo to the hotside, the cold side, the radiator hoses , and maybe the ignition coil harness if it’s too tight.

So you’re all here. I’ve invited everyone that “usually“ pays attention to this thread, which means I’m asking for your input.

On paper, the answer is almost screaming at me....I just wanted to see what the majority think. As fir now, I’m going downstairs to pull the transmission.