03/04 head swap

[K2AHollywood]

Dumb question but I am looking at throwing some 03/04 heads on my build - I have a good line on a deal that would make them cheaper than machining mine. My question is, will this be a direct swap or are there differences? Mostly I am concerned about exhaust ports to headers being the same. I don't feel like ditching my expensive Kook headers.

Oh and are the heads of an aluminator for block more special than the run of the mill termi head?

 

[01yellercobra]

The 03/04 heads will bolt right on. My first go round I had the 03 heads bolted to a Teksid block and used my 01 exhaust manifolds.

 

[jrgoffin]

Oh and are the heads of an aluminator for block more special than the run of the mill termi head?

All the head info is right here:

Castings

 

[99Cobra_vert]

Same here. I have 04 heads on my '99 Teksid. No mods needed whatsoever, but the 04 heads flow only marginally better than the 99/01 heads. If they are cheaper than rebuilding your existing heads, it is worthwhile. Otherwise, I wouldn't waste your time or money.

 

[na svt]

It's a direct swap.

 

[IUP99snake]

The only thing I can think of is that the newer heads have a different D shaped exhaust port than the earlier heads.

While headers and manifolds will physically bolt on to the newer heads, there may be differences in headers and manifolds designed for the newer vs. older heads.

Some people say that there are no port interferences, some people say there might be.

When I swapped to my current long block with the 03/04 heads, I wanted to play it safe, so I picked up a set of used exhaust manifolds from an 03 Cobra instead of using my stock manifolds..

 

[jrgoffin]

Exhaust manifold port differences:

 

[na svt]

The 93-04 manifolds can be used on 03/04 heads without any problems.

 

[K2AHollywood]

Same here. I have 04 heads on my '99 Teksid. No mods needed whatsoever, but the 04 heads flow only marginally better than the 99/01 heads. If they are cheaper than rebuilding your existing heads, it is worthwhile. Otherwise, I wouldn't waste your time or money.

They are which is the only reason I am considering the swap. Machining of current ones in my area is outrageous

All the head info is right here:

Castings

This doesn't really answer the question if there is and advantage to aluminator heads over the standard termi heads

 

[jrgoffin]

This doesn't really answer the question if there is and advantage to aluminator heads over the standard termi heads

You asked if the newer heads were "more special" - the link provides the information as to their differences. Make your own choice as to what works best for you.

 

[IUP99snake]

Exhaust manifold port differences:

Thanks for showing that pic. Everyone seems to think there's no difference, but this finally shows it.

I'm glad I "upgraded" to the 03 Cobra manifolds when I did the long block swap.

 

[na svt]

Thanks for showing that pic. Everyone seems to think there's no difference, but this finally shows it.

I'm glad I "upgraded" to the 03 Cobra manifolds when I did the long block swap.

I don't believe that "everyone" said there wasn't a difference. There is a difference but it's not enough to cause a problem and the 03/04 manifolds are definitely not an upgrade. If swapping them offers you some peace of mind then it was a good swap.

 

[tmhutch]

Too much of a mismatch for my taste, 99/01 exhaust on 03+ heads is not ideal. Is it worth spending a $1000 for the correct flanged header to pick up 3 - 5hp? Depends on the individual.

 

[K2AHollywood]

Too much of a mismatch for my taste, 99/01 exhaust on 03+ heads is not ideal. Is it worth spending a $1000 for the correct flanged header to pick up 3 - 5hp? Depends on the individual.

With what I spent to get these Kooks headers, plus the PITA to install...no way. Ill stick to the 99/01 head in that case. Thanks guys for all the help

 

[01yellercobra]

With what I spent to get these Kooks headers, plus the PITA to install...no way. Ill stick to the 99/01 head in that case. Thanks guys for all the help

FWIW, when I ordered my Bassanis the part numbers for the 99/01 and 03/04 were the same. So chances are your Kooks were sized for the 03/04.

 

[IUP99snake]

Too much of a mismatch for my taste, 99/01 exhaust on 03+ heads is not ideal. Is it worth spending a $1000 for the correct flanged header to pick up 3 - 5hp? Depends on the individual.

It's mainly stock manifolds that are the problem because they appear to be port matched to their heads.

I'm not sure if it's that big of a deal with aftermarket headers because they all have big enough flanges and tubes for both types of heads. I can't find any different part numbers for headers for the 99-01 heads vs the 03-04 heads. But this is certainly worth researching in greater detail.

I couldn't afford headers at the time so I just paid $20 bucks for a set of used 03 cobra manifolds "for the peace of mind".

 

[olgreydog7]

When my heads were ported, the exhaust ports were opened up to the 03/04 gaskets. The Hooker header flanges, that I bought in 2002, actually fit better now. I would not worry about it .