gasket match?

[3400-95-Modified]

I just lined up the holes when I did mine...

This is how much came off of mine. Worth the time with the amount of material that I removed...



And this is how much I took off the 3100 upper to match the 3500 gaskets.

[IsaacHayes]

I noticed my heads (94 stock) are pretty close to the gasket. Only two are a tiny bit off, otherwise they are dead on.

[ForcedFirebird]

I noticed my heads (94 stock) are pretty close to the gasket. Only two are a tiny bit off, otherwise they are dead on.

Mine only lined up on two sides (2004 3500 heads and GM stock replacement gaskets)...

[IsaacHayes]

Yeah those look like Jon's. Mine are better than that. Two of them have a corner that peaks out, but the sides/tops are all really close if not bigger than the gasket. Regardless your heads are better! lol

[93GAGT3300]

3400-95,

thanks for the pics of the 3500 intake. i notice that the ports are a little different that the big port 3100's . i wonder what was the reason for that change. good gasket match job though.

one thing i have noticed. if i had the time. i would have disassembled the heads and blended the bowls underneath the valve seat, especially on the exhaust side.

from the exhaust bowl straight through to the mufflers, i think gm used every possible way to restrict this motor from breathing.

the exhaust ports are ok, but they could be better at least gasket matched.

then for those who can't spened the moolah right now for the headers. the exhaust manifold, on the inside. they're a joke. everything is going to get opened up and smoothed out the best i can. the worst part is the rear manifold where it emptys into the down pipe. look inside that opening. can you say restriction? then the mouth of the down pipe is pitiful.

i'm going to fix as mouch i can humanly possible before i throw this engine back into the engine compartment.

[IsaacHayes]

2005 3400 impala manifolds are way hogged out like the 3500 port size. Get those and save your porting bits...

[93GAGT3300]

are you saying that the impala manifolds are BIGGER than the 2000 malibu ports?

[3400-95-Modified]

Yes

My 05 Impala 3400 I bought with 4k on it


Impala exhaust manifold gasket comparison to a 01 3400 gasket.


And how well it fits to the manifold... so that shows you how much bigger it is.


Oh and my head side porting job....

[IsaacHayes]

Wow, look at the gasket. They routed the edge seam around the coolant jacket ports instead of making it a straight line down. They did this so if the coolant jacket leaks, it forces the coolant to leak out the motor instead of inside. Haha interesting. I guess it makes room for the metal anti-crush tabs too. I'd still rather go metal felpro so the plastic can't break/warp and move the rubber in the first place. Too bad no metal 3500 felpro gasket is out yet.

[3400-95-Modified]

I have GM 3500 gaskets in mine the ones pictured... so far so good... Then again motor only has like 4k on it.

[ForcedFirebird]

Yes

My 05 Impala 3400 I bought with 4k on it


Impala exhaust manifold gasket comparison to a 01 3400 gasket.


And how well it fits to the manifold... so that shows you how much bigger it is.


Oh and my head side porting job....

I now can see what my heads are goimg to look like in the near future!!!

[93GAGT3300]

DAAAAAAMMMMMNNNNN!!!!!!

the 3500 intake and exhaust ports made the 3100 big ports look like the 3100 small ports.......

has anyone fitted 3500 heads to a 3100 set up? can it even been done. now i feel i should have gone THAT route. one other question, would my injectors from my 96 set up even keep up with the demand of fuel with a 3500 set up?

[bszopi]

No, 3500 heads will not work on a 3100 engine. They will bolt up and all, but the combustion chambers go past the cylinder bore and onto the deck surface (which is not a good idea).

[93GAGT3300]

oh well, so much for that idea. will 3400 heads fir on the 3100 block without issues?

[IsaacHayes]

Yes 3400 heads fit on a 3100 fine. (In fact 2000+ 3100's have 3400 heads on them). It's just the 3500 are too big for anything but a 3400.