Preparation for heads, uim, camshaft and downpipe

[SappySE107]

Yeah, that shouldn't change at all for the alt. The 3400 can't go much bigger than 65 and the 3500 can go 70 at least. I don't know what the max is, but 75 might work too.

[skinrock]

Quick question, I didn't even think about this. I just ordered a 200 amp alt for my 3400...does the stock alt still fit on the 3500 top end swap (stock UIM). In other words, if I ordered the alt for a 3400, is it going to fit when I swap for 3500 heads and lim?

[ForcedFirebird]

You would need the option for porting the TB part of the plenum to match a 3400 for the 65mm TB.

How big can the 3500 plenum be ported? Actually, the 3400 as well?

[SappySE107]

You would need the option for porting the TB part of the plenum to match a 3400 for the 65mm TB.

[skinrock]

So, I should buy the ported 3400 UIM on this store if I get the 65 mm TB, and everything will fit right?

[IsaacHayes]

The 3500 plenum will need clearancing for the FPR. Using a 3400 UIM will bolt right up without much problems. You gotta re-use your 3400 fuel rail and injectors. The 3500 plenum also needs the evap port tapped and T'ed off for vacuum for the FPR and transmission. And you gotta re-wire for the new MAP or use the old with some vacuum tube. And you need a TB adapter. If you don't have all that stuff ready to go, just find a large port 3x00 UIM so you can get out of his shop quicker and put the 3500 on later once you get all the stuff for it.

[whitelightnin04MC]

Good to know.

[Superdave]

I don't know a whole lot about it, but after the header install, it just seemed to me that swapping heads would be a WHOLE lot easier with the motor out.

with air tools i had the whole top end of my old 2.8 off in under 30 minutes...


It's very simple to do in the car...

[onefastV6]

I don't know a whole lot about it, but after the header install, it just seemed to me that swapping heads would be a WHOLE lot easier with the motor out.

I have swapped heads 3 times with the engine still in the car.....pulling the engine to do heads is going to take twice as long and be twice as hard in my oppinion.

The best thing that I found to do is to install the exhaust manifolds on the heads before you bolt them to the block.

[whitelightnin04MC]

There is no reason to pull the motor just to swap the top end.

I don't know a whole lot about it, but after the header install, it just seemed to me that swapping heads would be a WHOLE lot easier with the motor out.

[whitelightnin04MC]

Ok, and what about the downpipe? I know where the cat end of the pipe is, I saw that when we did my dual exhaust, but I've never actually seen where the other end goes. Is that a hard to get area?

Nah man, where the downpipe bolts to the exh. manifold is really easy to get to. All you need are a couple of long extensions.

[skinrock]

Ok, and what about the downpipe? I know where the cat end of the pipe is, I saw that when we did my dual exhaust, but I've never actually seen where the other end goes. Is that a hard to get area?

[ForcedFirebird]

There is no reason to pull the motor just to swap the top end.

I agree

[SappySE107]

There is no reason to pull the motor just to swap the top end.

[whitelightnin04MC]

Your best bet would be to buy a cheap 3400 on ebay and build that motor up. Even if it is possible to swap heads with the motor in the car, it'd probably be MUCH easier to do with the motor out.