73 Blazer and a 454BB... TBI or what?

[KeyBlazer]

Today I pulled a 454/TH400 out of a 1990 3/4t Suburban.
I took the whole lot... Engine, trans, A/C and all the wiring, sensors and Computer.
Plan is to do a 454 conversion in my 73 Blazer sometime.
I have searched and know the basics.
The motor will be rebuilt... maybe even stroked and some better heads/cam.
I have some nice headers in my storage that will fit...
Questions

1/ Should I swap it in with the stock TBI, or swap to a carb or something else? The 73 is Smog exempt her in CA now.
2/ Should I take the 14bolt axle as well?
3/ Should I take the whole A/C system?
4/ Anything else I should grab off the Suburban while I have access to it?

 

[dyeager535]

Was it 4WD? I'd say grab the t-case and cluster, you'll need it for the electronic speedometer, which is far superior to the old mechanical stuff. Oh yeah, tank and fuel lines too, if it's not the 40 gallon tank. (you'll still want the sender and pump though if it's cheap/free) I suspect at least the lines from the filter forward are the same no matter which truck.

I certainly say go with TBI, you'll have a hard time finding anyone who has swapped to EFI that regrets it. You'll need a chip burned after it's all put together of course, but that's not a big deal.

This is a good chance to figure out an enduring question if it's got the 40 gallon tank...why GM says the sender isn't interchangeable in the 31 gallon K5 tank, which is the same depth.

 

[KeyBlazer]

Its a 2wd, and I think its the 40 gallon tank.
What will I need for the 4wd?
My Blazer is a 350/th35/np205.
Is the adaptor for the TH350 to NP205 the same as the one for the th400/np205.

 

[rdn2blazer]

yes, get the 14FF.

 

[dyeager535]

No, adapters are different.

You'd need the NP241 from '90-91, which makes it a bit more difficult in your case. If you are doing the entire wiring, I'd seriously consider it though.

Had I known better when I started, I would have gone the 241 route myself. The 205 was available with the VSS in the tailhousing for one year, so it's pretty hard and expensive to find, but you can convert the earlier ones I hear. Might be an idea since it would save you all the driveshaft and shifter issues of changing cases.

 

[KeyBlazer]

Why do I need the NP241?
I already have a 205, which I thought was a good TC.
Cant I just find the adaptor for a th400 to 205... or am I missing something?

 

[Busted Knuckles]

If you'd like to bump performance, get some big oval heads (781's or 049's) and an intake that fits 'em. Adapt the TBI to it, run a cam in the 215 - 220 duration range with a 114LSA for good vacuum, get a good tune and you'll have a permanent grin!
As for the rest of the stuff...when in doubt, scavenge everything you can get!!!

 

[Boscolingus]

You would need to retain the 241 in order for the VSS ( electronic vehicle speed sensor ) to feed info to the updated ECM and cluster, any chance to improve/update a vehicle is absolutely worth it

...and grab the 14 bolt!!!

 

[BulldogK5]

What everyone else has said along with get the 14 bolt. I believe the 'burbs only had a 14bSF that year but I could be wrong. Either way it is an upgrade to the 10b.

 

[KeyBlazer]

Been offered a pair of heads... casting is 14081045
Here is what Mortec says:

14081045...78-87...oval...OPEN...454

Worth getting?

 

[Busted Knuckles]

There are only a couple of "peanut" castings - the old -236 and 14092360. Peanut ports are easy to recognize - they're almost the exact height as width where the oval is definitely taller than wide. Post a pic if you get a chance, but those sound like they'd probably work for you.

 

[KeyBlazer]

On the websites it does not say anything about this head casting number... good or bad!
The production years tell me that it will have hardened seats, so thats a start, and that it has an open chamber and oval ports...
I just need to know if it will work and if it is an improvement...

 

[Thunder]

I dont think they are any better than the heads you have on the 90 block. All the BBC oval heads after 1976 were peanut port except 781s which are the large oval.
As said above 049 or 781 are the numbers you need for performance.
The 045s you are looking at are just basic peanut port smog heads.

Re the Xfer case. You can get a chip with the VSS deleted and use any xfer case you want. If you do any performance mods to the engine you will need a new chip anyhow.

 

[Busted Knuckles]

Shoot a pic or two of the intake ports and the chambers, either post 'em here or email 'em to me at [email protected], I'll be glad to take a quick look at 'em and let you know if they're worth the time/$ investment.