Hey guys!

I'm looking too those of you who are further enlightened than I am.

I was having a little think in my head earlier on today. Has anybody to this date attempted to slam some 380 heads onto a 3.0 V6?

Being that the 380 heads have better flowing capabilities over the 72/74 heads, it might be just as easy to put the heads on in one piece with the cams included?

Thoughts and ideas please!

If your going to the effort of buying and changing over the heads why not throw the whole 6g75 in ? Surely it wouldnt cost much more than a good set of heads anyway.

i know a 380 head on a 3.5 :) PM life he got a all the info :)

afaik you lose a lot of compression if a head swap is all you do, it has a larger chamber volume than the 72/74 heads

i know a 380 head on a 3.5 :) PM life he got a all the info :)

Pass on that thanks as life has not done this so would not have a clue

As above why bother as you will only have even less compression and a heap of cost

My Wrecked AWD had 380 heads and cams on the 3.5

To be honest, it didnt drive, feel or sound much different to the normal heads. Apparently the compression is very different when you do this

Shoot me down in flames next time guys!

I didn't realise that they would lower the compression.

Thread cleaned up... I've deleted a lot of posts that held no relevance to what the original question asked.

Have a read of this. (http://www.aussiemagna.com/forums/showthread.php?t=89946)

It's not related to the '72 engine exactly but it's along the same lines...

Putting a head from a smaller engine eg a 3.0 or a 3.5 onto a 3.8 would give you a higher compression ration and therefore more performance. This assumes that everything else would be equal. It used to be an old trick with the old 179 Holden engines - the boys would put a head from the smaller engine (cannot remember its size - 141 I think) and they got a good boost. So to go the other way would certainly be a waste of time unless you were to put a turbo or supercharger on, in which case you would probably need to reduce teh compression a bit to avoid long-term damage to the engine.

Putting a head from a smaller engine eg a 3.0 or a 3.5 onto a 3.8 would give you a higher compression ration and therefore more performance. This assumes that everything else would be equal. It used to be an old trick with the old 179 Holden engines - the boys would put a head from the smaller engine (cannot remember its size - 141 I think) and they got a good boost. So to go the other way would certainly be a waste of time unless you were to put a turbo or supercharger on, in which case you would probably need to reduce teh compression a bit to avoid long-term damage to the engine.

This is not the case for every car. Deck height difference between the 72 and 75 is likely to be the reason

Shoot me down in flames next time guys!

I didn't realise that they would lower the compression.

Yes,but by how much

Yes,but by how much

Doesn't matter, if you lose compression you won't gain anything with the heads to make up for it.

Also not much point without the 6G75 inlet manifold and piping...
Swap the whole engine or don't bother :P

Yes,but by how much

Total swept volume to combustion chamber volume = compression ratio. Get the numbers, work it out.