Mikethe

I would really like to swap out my 350 TBI for a 1990 454 LS6. I have a 1990 Silverado so I am thinking it should be a direct bolt in with not much modification required. Has anyone had any experience with this type of swap? Would it be very difficult? Thanks

Mike

DirtySnowBird

iTrader: (3)

454 ls6???????

GreenBlood

iTrader: (6)

ummmm, can i ask wtf you are talking about? the 454 from 1990 was definitely not an LS6...

adillhoff

There is a great search button on this site. You can learn all about the LSX motors and what year they were manufactured. I highly recommend you read up on your motors, good sir.

blazerboy72

iTrader: (9)

There was a 454 LS6 but as far as I know they quit making in the early 70's.

tirefryin_s10

iTrader: (3)

And i suggest you do some more research before pouncing on people ... there is such a thing as a ls6 454 and it came out LONG before the current ls6 ,Although I think he was refering to the later 454 such as whats found in the 454 ss ..... if so yes its a direct swap you just need to find all the bbc parts most can be had off of a 3/4 tonne that had the big block.

Toss the manifolds buy some long tubes and the rest should be straight forward going carbed would be the easiest/best power but if you want to retain the tbi injection i think you can either re flash the pcm to accept the big block programming or you may have to replace the pcm /harness.........that aspect im not too sure on

Mikethe

Sorry about that I guess what I meant was a 1990 454 TBI made for the 1990 ss's. I had just thought that the 454's were LS6's, my bad.

Mikethe

So, for the most part the feedback I am getting is that the 454 is'nt going to do much for my truck. I am really looking for something that's going to get my truck going. I am not sure if an LS1 swap would be as easy as a 454, any ideas?

G-Body

iTrader: (4)

It all depends on how much power you want and how much modification you want to do. The 454 from a 1990 SS would probably be the easiest swap, but if you don`t already have one it would probably be difficult to find a complete 454 from the SS truck as I don`t think they made a lot of them. The 454 probably has the most power potential if you are willing to really build it up, the 454`s out of the SS trucks had "peanut port" heads on them which are horrible for performance use so those would have to be ditched if you were serious about making power. A LS1 swap would require more work to bolt in, but it would make more power than the 454 as a stocker, and mod for mod it would probably be cheaper to make power with the LS1 until you hit ~500-600hp, from there up the 454 would be cheaper per HP. The LS1 will also get better fuel mileage. Another option would be a vortec 5.7L from a 96-98 truck, they make 255hp from the factory and are good till about 375hp(after that the injectors are maxed out and there are no larger injectors available for this motor), the vortec 5.7 would be a little easier to swap in than an LS1.

Mikethe

Thanks for the info

Mikethe

I have another question. I have seen allot of people talking about notching the frame or having to do some sort of fabrication to the frame because of the A/C compressor. Does anyone know if this fabrication would still be needed if I decided to remove the A/C??? Honestly I always ride with the windows down, unless of course it is raining, so I ussually do not need A/C. But if I were to keep the A/C would the fabrication be minimal or would it require the help of a profesional???
Thanks for the help

Mike

G-Body

iTrader: (4)

If you remove the A/C you will not need to do any fabrication for the A/C. The compressor is on its own mounting bracket and its own belt. You may also be able to use your current setup, I know that your truck came with the R4 radial compressor, if it is on the passenger top side of your current motor the hoses should even work. If you use a f-body LS1 you can buy a bracket to mount an R4 compressor on the LS1 from f-body motorsports. If you decided to use a truck LSx (4.8, 5.3, or 6.0L) (they are all derivatives of the LS1) you could use a a/c compressor bracket from a 4.3L V6 s10 series truck and replace the tensioner pulley with one from a 4.6L mustang and it will work (5.3 Racer used this setup on his 6.0L cutlass)