454 & 400 turbo

[LipRipr]

My 84 has no guts. Has a stock 350 in it. I have a 454 just dying to get installed in this 84. The 454 has been in my 78 & 77. Both had turbo 350s. Is the bolt pattern the same on the turbo 400 for the flexplate & torque converter?

 

[HotRodPC]

Easy bolt in swap. I think the clam shell motor mounts is about all that has to be done, and the crossmember should line up with a different set of holes already punched in the fame to accomodate the Th400. Though IMO, the 454 if it's got peanut port heads, isn't going to give you the gain you think it will. Personally, I've liked the attitude of my 350/Th350s better than the 454/Th400. IMO, the The OEM 350's just seem more spunky, like the higher rpm and make them more fun. Only time you'll notice any gain with an OEM Peanut Port headed 454 is if you're towing something. Now do a head swap and an RV cam and intake on the 454, total different ball game. You'll wake that bitch up.

Just saying, unless you put some adders on the 454, just don't have high expectations for a performance gain unless your 350 is totally wore out and done having fun.

 

[LipRipr]

Oh, it's awake
This is a 1974 454 w/ oval port heads. I had it ported about 15 years ago & had a big lumpy cam that shook the steering wheel, sounded awesome, also has flat tops & other perf items. It would absolutely fry the tires on my 77 3/4 ton. When it was in my 78 1/2 ton all I did was break stuff, all the time. Always had my foot in carb. I've ruined a 350 turbo in each of those trucks.

Now, I've put in a 272 cam & is much more "normal". Hope the 400 turbo converter bolts right up. And I'm much older now & for the most part am able to keep my foot out of the carb.

 

[MadOgre]

The 454 will make the front end of your 4x4 ride nice and smooth unless you have saggy front springs. Especially if you have lifted springs! If the 4x4 adapter is the same style as the TH350 it should bolt up in the same holes in the frame. The holes usually only move if you use a different style cross member.

You'll need a transfer case to match that TH400 or else you'll have to change out the input gear from a 27 spline to a 32 spline

As for the torque plate to converter, It should bolt right up.

 

[cooter55]

I love my 454 with the "049" heads, cam, headers, and fuel injection. That's my vote.

 

[LipRipr]

The 454 is in & running. The flexplate to 400 torque converter & motor mounts bolted right up. Had to cut the fan shroud. Couldn't even begin to get it on because the 454 is about 3" longer than the 350. The aluminum cover that protects the flexplate & converter needs trimmed at the crank & pan. The U is too narrow for that big crank. Nothing some grinding can't fix.