Big decission: Which conversion kit to buy for my 78 FJ-40's new (not so new) 91 350 TBI engine. One kit from AA (P/N 713024-EK) requires the engine, transmission and transfer case to move forward thus requiring the drive shaft modifications and gear shift lever relocation. It costs $641. The other kit from AA (Marks P/N 713025-EK) doesn't require any modification to the transfer and transmission location. But it cost $1407.
350 TBI Conversion: 2 move or not 2 move the transmission
- Thread starter JAG65
- Start date
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dgangle
total rice
Having researched this before, my humble suggestion is for you to read up on both and base your decision on budget, abilities, needs, desires, ramifications, advantages and your intended use when you are done.
To me, moving then drivetrain forward and modifying the driveshafts and shifters was not worth the price difference of the 2 methods. That $766 difference buys a lot of creativity.
Talk to Advance Adapters. They sell both and can give you the lowdown. They have been very helpful to me in the past.
From their website:
Marks P/N 713025-EK
This adapter kit is used to adapt a Chevy engine to FJ40, FJ45, FJ55, FJ60 and FJ62 4 and 5-Speed Manual Kit and is manufactured by Marks 4wd. It utilizes the GM flywheel and clutch along with the Toyota bell housing. Instead of a new bell housing, a flywheel housing is supplied which measures 4.8" long. This housing has the GM bolt pattern on the front and the Toyota 1F, 2F, and 3F, bolt pattern on the rear.
The kit has been designed to allow for firewall clearance without shifting the transmission or altering the drive shaft lengths.
The transmission input shaft is coupled to the clutch via an input extension shaft. The shaft has the Toyota internal spline and pilot diameter on the transmission end, and GM external spline and pilot diameter on the engine end. The front of the shaft is supported in the crankshaft by a sealed ball bearing inside an adaptor ring.
We also include GM weld-in engine mounts, bell housing mount, throw-out bearing & pilot bearing with this kit.
Note: Conversion clutch pressure plate & disc are sold separately.
To me, moving then drivetrain forward and modifying the driveshafts and shifters was not worth the price difference of the 2 methods. That $766 difference buys a lot of creativity.
Talk to Advance Adapters. They sell both and can give you the lowdown. They have been very helpful to me in the past.
From their website:
Marks P/N 713025-EK
This adapter kit is used to adapt a Chevy engine to FJ40, FJ45, FJ55, FJ60 and FJ62 4 and 5-Speed Manual Kit and is manufactured by Marks 4wd. It utilizes the GM flywheel and clutch along with the Toyota bell housing. Instead of a new bell housing, a flywheel housing is supplied which measures 4.8" long. This housing has the GM bolt pattern on the front and the Toyota 1F, 2F, and 3F, bolt pattern on the rear.
The kit has been designed to allow for firewall clearance without shifting the transmission or altering the drive shaft lengths.
The transmission input shaft is coupled to the clutch via an input extension shaft. The shaft has the Toyota internal spline and pilot diameter on the transmission end, and GM external spline and pilot diameter on the engine end. The front of the shaft is supported in the crankshaft by a sealed ball bearing inside an adaptor ring.
We also include GM weld-in engine mounts, bell housing mount, throw-out bearing & pilot bearing with this kit.
Note: Conversion clutch pressure plate & disc are sold separately.
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I opted on the AA kit but I was already going with the 700R4 tranny w/ stock TC. I'm happy with the AA products and they were very helpful during my install.
nick
nick
dgangle
total rice
Good point Nick. Obviously if not using the manual Toyota 4 or 5 speed, there is no reason to even consider the Marks adapter.
- Thread starter
- #5
Thank you for the responses. Clearly $700 is a considerable difference. I have priced the cost to modify the driveshaft lengths--about $100 each. That still gives me $500 to spare. My main concern was the extent of the modifications. This is my first swap and I want to ensure that I'm successful. If the Marks kit is that much easier, it might be worth the $500 difference.
I have the Marks kit sitting in the garage with a centerforce clutch. I picked it up very slightly used,in fact the clutch and pressure plate still look new. I changed plans on the project and will not be using the adapter. If you are interested in buying a Marks kit let me know.
dgangle
total rice
Assuming the price was right, I'd be jumping all over that.
View attachment marks adapter instructions.pdf
I used a Downey kit (same as AA kit)... Only conversion I've ever done. It was very straightforward. If you use the top cover off a 60 series transmission, your stick shift can remain in the same place. (moves the stick back +/- 4")
Other notes:
shortening shafts is always cheaper... If you've got a spare from one.
if my engine was back 1/2" further my front and rear shafts would be interchangeable.
Spark plug sockets with a built in u-joint allow easier acces to the plug behind the steering box (popular mechanics makes one that used to be sold at Walmart).
Other notes:
shortening shafts is always cheaper... If you've got a spare from one.
if my engine was back 1/2" further my front and rear shafts would be interchangeable.
Spark plug sockets with a built in u-joint allow easier acces to the plug behind the steering box (popular mechanics makes one that used to be sold at Walmart).
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dgangle
total rice
if you end up using the AA kit and moving the drivetrain I have perfect front and rear driveshafts already modified/balanced I will sell for $100 plus shipping from 35242. These were from my '75.
Here shortening/balance is ~$75 and lengthening/balance is ~ $150. Just sayin'.
Here shortening/balance is ~$75 and lengthening/balance is ~ $150. Just sayin'.
On my '79 we have just removed a V-8 350 conversion and see the Chevy bell housing is bolted on. My goal is to install a stock 2f of a '77 FJ40 and get the rig into it's original state. Now I need to get rid of the motor, the idelbrock weber carb , headers and bell housing first plus the welded in motor mounts. I think the rest is stock.
I sent you a PM about the parts with my phone#. Call me and we can discuss what I have.
