231 Rear Wheel Drive SFI BOP V6

To all, I have a 1970 Jeepster Commando currently equipped with a 225 Buick Dauntless V6, I would like to do an update and put in a 231 even fire fuel injected V6 with a 4L60 transmission. My problem is finding out what years and models where built using the rear wheel drive block and where fuel injected. I would prefer the SFI over the throttle body type of injection. Also if someone knows of specific casting numbers that Identify the correct block that too could be helpful. Any help in identifying possible donner cars would be very helpful. Thank you. Mark.

most 231s are "even fire". i believe it was only the first year and a half or so of production that used the 225 "odd fire" pattern and crank.

given that you want factory fuel injection, that's going to mean looking for a 3.8L designation as Buick did away with the 231ci nomenclature in the Seventies and FI wasn't implemented until the mid 80s.


in fact, don't think GM offered FI on the "3.8L" displacement
...
unless you're going to with a Turbo v6 from a mid-80s Regal!

https://en.wikipedia.org/wiki/Buick_V6_engine#LD5


otherwise, if you're REALLY fixated on this FI idea, you're actually going to be looking at a newer engine in the 3800 series.

there is also a 4.1L displacement from the early 80s, but those are all carb engines. it's the LC4 on wikipedia.

Quote:

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Originally Posted by kd6kyy@email.com

To all, I have a 1970 Jeepster Commando currently equipped with a 225 Buick Dauntless V6, I would like to do an update and put in a 231 even fire fuel injected V6 with a 4L60 transmission. My problem is finding out what years and models where built using the rear wheel drive block and where fuel injected. I would prefer the SFI over the throttle body type of injection. Also if someone knows of specific casting numbers that Identify the correct block that too could be helpful. Any help in identifying possible donner cars would be very helpful. Thank you. Mark.

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Sorry, but your best bet would probably be a TBI system. Aftermarket, like Howell or the Holley Sniper system. I wish I could bring you better information. Then again, I have been wrong many times.

Bob, Thanks for the information I may just forgo the replacement engine all together as I can go through my 225 and add Howell Fuel injection in the form of TBI and get most of the advantages of Fuel Injection. I was kinda of hoping there was a multiport fuel injection package with a 4L60 behind it that I could go through and update and swap in as a replacement. Will still have to think about the 4L60 the overdrive would be nice. Thank you for your thoughts. Mark.

Quote:

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Originally Posted by bob k. mando

most 231s are "even fire". i believe it was only the first year and a half or so of production that used the 225 "odd fire" pattern and crank.

given that you want factory fuel injection, that's going to mean looking for a 3.8L designation as Buick did away with the 231ci nomenclature in the Seventies and FI wasn't implemented until the mid 80s.


in fact, don't think GM offered FI on the "3.8L" displacement
...
unless you're going to with a Turbo v6 from a mid-80s Regal!

https://en.wikipedia.org/wiki/Buick_V6_engine#LD5


otherwise, if you're REALLY fixated on this FI idea, you're actually going to be looking at a newer engine in the 3800 series.

there is also a 4.1L displacement from the early 80s, but those are all carb engines. it's the LC4 on wikipedia.

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To chime in here behind Bob K Mando, the closest match would be a 3800 series II SFI L36 engine from a '95-02 Firebird or Camaro. That one uses the 4L60E electronic version automatic.

The '95 unit uses the older OBD I diagnostics. That year was for California only and could be scarce.

the 200r4 trans is the common swap if you want an OD automatic onto a 225ci or 231ci.

and all of those should have dual pattern bells, so any of them should fit your engine.

Does anyone know are the motor mounts cast on the block on these "F" body cars the same as the old 225 V6? If so this should be a great fit for someone wishing to do an upgrade to a newer FI engine in an older vehicle. And were these also rear oil sump setups? Thank you. Mark.

And were these also rear oil sump setups?


i don't know for certain, but it would be hard to imagine that they're not.

sump location is determined by how the engine is positioned in relation to the front crossmember, and the Buick v6 is just a small block Buick with the front two cylinders knocked off. ie - the bellhousing and trans are located in exactly the same place they would be if the car had a Buick 350 in it. there shouldn't be any part of the block far enough forward to be able to hang over the crossmember.

remember, these year Trans Ams also fitted 350 SBCs.

so far as mounting location, TAPerformance.com can probably answer that question as they supply brand new aluminum v6 block castings.


https://web.archive.org/web/20170613...et/ttahist.htm