engine swap

[jr4450]

i have an '89 K-5 that right now has a 5.7 V8 tbi and auto trans, but i want to swap it out for a '73 454 with 3 speed, will they match up or is this just hopeless dreams?

 

[Jims86]

i have an '89 K-5 that right now has a 5.7 V8 tbi and auto trans, but i want to swap it out for a '73 454 with 3 speed, will they match up or is this just hopeless dreams?

454 and trans should bolt in, there may be a difference with the trans case adaptor, but everything will fit in the truck just fine. What are your plans for a fuel system?

 

[jr4450]

i honestly haven't gotten that far. My tank is good and holds 30 gal so i might just run new lines from it. im not racing or anything just want more power for deep mud and my 350 is smoking so i figured i would just swap engines

my main concern was the trans fitting, i didnt know if the length would be different, the motor and trans are coming out of a 2wd short wheel base dually and going to the k5, but i was also thinking i might take the rear axle with it since its a solid locked 1 ton

 

[Jims86]

i honestly haven't gotten that far. My tank is good and holds 30 gal so i might just run new lines from it. im not racing or anything just want more power for deep mud and my 350 is smoking so i figured i would just swap engines

my main concern was the trans fitting, i didnt know if the length would be different, the motor and trans are coming out of a 2wd short wheel base dually and going to the k5, but i was also thinking i might take the rear axle with it since its a solid locked 1 ton

What I am getting at is: Are you going to carb the 454, or Use TBI?
As far as lenghts are concerned, I am not 100% sure. I would measure the distance between the mounts, and the end of the trans on the 350 drivetrain, and then measure the same points on the 454.
Many have swapped from small to big block, using their existing Trans, but it may help to know what trans you have now, and then we can collectively make suggestions based on experience.

 

[jr4450]

oh i got you now... no i am going to carb the 454. i already have it bored and im going to put a snorkel on the intake. the trans i have now is the 700r4, and the one on the 454 i have no idea all i know is it is a 4 speed with granny low

 

[Jims86]

Ok, I just wanted to be sure. If you need to find a place to keep That EFI stuff from the 350, let me know...I like to keep stuff on hand for projects and just incase anyone else needs anything...I dont sell the stuff, I just make sure it works and send it out....it keeps me tinkering, and keeps me from loosing my mind.
The trans on the 454 sounds like an SM456, let me get HR over here, he is our Trans and driveline Jedi.

 

[HotRodPC]

Yeah, it's a Chevrolet, you can bolt any Chevy Bell Auto trans and any GM manual trans you want to any motor via Chevy Bell Housing. So you must be saying you have a 700r4 now? and want to go to a 3 speed auto? If going 454, Th400 would be better, but Th350 will work too, and with a spacer, you can use your same Tcase. Otherwise you'll need to find a Th400 adapter and either a 32 spline Tcase or swap inputs on yours, assuming it's an NP208. Best idea, would be to keep your eyes peeled for a Th400/NP205 setup.

 

[HotRodPC]

Just reaiized were talking an 89, you've likley got NP241C. Almost lateral to the NP208 though. Same/Same.

 

[8T6K5]

454 and trans should bolt in.

Bolt in yes, but I think the radiator will need to be moved (towards front)?

I think theres a thread in here where someone dropped a 454 in a K5? I looked and couldnt find it.

 

[Jims86]

Bolt in yes, but I think the radiator will need to be moved (towards front)?

I think theres a thread in here where someone dropped a 454 in a K5? I looked and couldnt find it.

I dunno about moving it, I do know that the 454 radiator is wider, but all squares are prepped from the factory to us SB or BB radiators...just need to move the upper mounts to the outer bolt holes, which already have the blind nuts in place. It was Austinado with his Burb I think....using a Bb rad on his 350.
I think he actually had to use a spacer for his fan because of the difference in the shroud.

HR, i think he was saying the 454 trans he wants to use is a 465 manual.

 

[HotRodPC]

NO, it shouldn't need moved, but a different radiator brackets are needed for the taller radiator. SqBody radiators come in 2 different heights.

 

[bucket]

A 2wd trans will not work in your K5, you need a trans from a 4x4. If you want a 3spd with granny, get a SM465/NP208 combo because it will be a direct replacement for your 700r4 and you can use the same shafts.

 

[Jims86]

A 2wd trans will not work in your K5, you need a trans from a 4x4. If you want a 3spd with granny, get a SM465/NP208 combo because it will be a direct replacement for your 700r4 and you can use the same shafts.

Cant he pull the tail housing off and use the T case adaptor?

 

[HotRodPC]

Cant he pull the tail housing off and use the T case adaptor?

NOPE, has to be the 4x4 output shaft and matching adapter with matching coupler. And there are 2 different 4x4 units, one it a 10 spline course in the early units and one is 32 spline like Th400 in the later units.

 

[Jims86]

NOPE, has to be the 4x4 output shaft and matching adapter with matching coupler. And there are 2 different 4x4 units, one it a 10 spline course in the early units and one is 32 spline like Th400 in the later units.

There ya go....why not have the 700r4 built up?