Might be out there already, 454 swap into 89 sub

[Grumpy Grizzly]

Couple questions. Will it direct swap at engine mounts? Recommended radiator, torque converter for the th700r4, and will be going to carb for trial run till 500 miles then tbi. The 454 is a motorhome 77 model. What should I look for with the hidden issues? Sorry if this was covered before just couldn't find anything

 

[Rickf]

Yes, direct swap. 3 core minimum radiator. Not sure how long a 700r4 will last behind a big block. A th400 w/a gear vendors od may be a better choice.

 

[Craig 85]

I have a OEM 4 row in my K30. I have a 195 thermostat due to emissions and have no issues with overheating. Here's a picture of the core support cover.

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[Grumpy Grizzly]

Thanks Rick, that makes me a bit happier and Ive been told that most heavy duty 1 tons have a 700r4 in them with no issue but i do have my trepidation still.

Hi again Craig. Do you have a model # and is it from LMC or Chevy themselves for that radiator? Also that engine bay looks really good, nicely done!

 

[Rickf]

I have had several K30's, w/automatics & none have had a 700r4.

 

[Grumpy Grizzly]

I have had several K30's, w/automatics & none have had a 700r4.

Hmmm, ok my transmission source is flawed then. lol thanks for the info I was wondering if it would hold up with thinner gears than the 400.

and this is why im here cause you guys know from trial and error.

Oh how much more room will I need for the over drive, if any? thinking drive line length.

I'm also thinking of a 4 or 6 inch lift on this girl too so the OD might help me not have to buy a new drive shaft. Also CV or no CV rear Drive Shaft? Im thinking no with 4 inch and yes with 6in. am I wrong on that?

 

[Craig 85]

My radiator is the original one to the truck. I just had it rodded out and repainted, so I don't have a part number. With regards to lifts it depends on you tire size and what you want to do with it. I've had 5 lifted square bodies. I prefer a 4" myself. They ride a little better than the 6" lift. I'm also getting older and getting in and loading things into a truck that is about 3" taller (6" / 35" tires) is kind of PITA. The K5 had a 6" lift with 36's. The K20 had a 4" with 33's.

I didn't include the K30 cause it doesn't directly relate to a Suburban frame. It only has a 3" lift, but with the K30's taller frame the lift is about 5".

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[skysurfer]

If the burb is a V series there might be an issue with motor mount brackets. I've never seen a '89-91 4x4 burb with a factory big block but there's a part number for the engine mounts on vehicles equipped as such.

https://www.gmsquarebody.com/threads/88-91-suburban-4x4-motor-mount-brackets.15654/

 

[Grumpy Grizzly]

If the burb is a V series there might be an issue with motor mount brackets. I've never seen a '89-91 4x4 burb with a factory big block but there's a part number for the engine mounts on vehicles equipped as such.

https://www.gmsquarebody.com/threads/88-91-suburban-4x4-motor-mount-brackets.15654/

Nah mine is the R1500 series. so I'm sure it'll work but meh ill find out when I try to slap the new baby in.