GIL sbc exhaust?
 

Can anyone tell me about the old GIL sbc aluminum exhaust manifolds with stainless risers? Were they a decent design? I have a chance to pick up a new in the box set from a local guy. The risers are not a long tube design but appear to be a direct stock replacement.

Here's what the risers look like...

https://cimg1.ibsrv.net/gimg/www.off...a84da7ccd4.jpg

Gains will be very minimal if at all on a SBC.

I agree with Griff. Been there done that.

Nope. About 80lb's lighter though...all said and done.

What did they do to that poor riser ?

BTW: What are you attaching these too (ie: what motor), maybe we can help.

https://cimg8.ibsrv.net/gimg/www.off...8e423c8efb.jpg
mine worked good but were dry to the tip

If you have the old log exhaust then I would switch to the Gils simply because of the age of yours.
If you had the Merc cast iron center rise exhaust, then I would leave them.
I still doubt you will gain anything performance wise.

These will be replacing the aging old stock log manifolds, that's the main reason for the swap. These GIL's will cost me less than a new Merc cast iron center rise setup. The engine was built from a Quicksilver reman long block for the previous owner. Quicksilver part#: 87971R5 Bore is listed as - 040 on the tag so I think that's a 358? Its all stock except for the Edelbrock Performer EPS intake (Part # 2701) and the Edelbrock Marine Series 600 cfm, Square-Flange, Electric Choke Carburetor, non-EGR (Part # 1409). I just have been enjoying it as is for the last few years since I picked it up.

https://cimg6.ibsrv.net/gimg/www.off...c9a356b008.jpg

FYI: The new wet joint Mercruiser center rise exhaust kit can be had for near/under $700, but they are cast wrong and can/probably will leak. The new replacement from merc won;t be out for a month. Hopefully those are cast right.

I know right! I have seen that riser on a GIL BBC manifold before but I thought it was a custom riser, I guess this design may have been an optional riser. I wish it was a smoother bend in the riser. But for the price i'm not complaining. I'll know once I bolt them up and see where they are pointing, the height, distance to transom, etc. I'm not sure but I think my current thru hull Hardin Marine tips may be 3" or 3.5" on the inside of the transom and 4" on the outside of the transom, at least that is what it looks like. I never checked them. A while back I picked up a set of GIL thru hull slash cut tips with the internal auger baffle I planned on using.

Are those a cast aluminum riser with a stainless tail? I like them! Nice smooth bend in them! Dry to the tip would be nice but on my lake that's a noise ticket waiting to happen. I've never been bothered with my thru hulls with a baffle insert.

I think I am going to need a new thermostat housing? I was thinking maybe the Sierra stainless steel 18-1989 thermostat housing. What you guys think?

<img src="https://cimg4.ibsrv.net/gimg/www.offshoreonly.com-vbulletin/1460x2000/cig_28_mmmm_9e8bf9921bdef2093ed99d5986904181db600c c8.jpg"/><br />actual the bb tails fit the sbc gils .. mine were aluminum and really old style....and I ran gaffrig mufflers with the water dumping directly in the muff. it was pretty quiet..only pic of the mufflers i had

Good thing you mentioned this. Do a search here on it. Complete disaster last few years or more. Definitely a 'how the hell can you mess this up' sort of thing. :(

Good to know the BB tails fit the SB manifolds, thanks for the tip!

Yeah, I figured I would need a new one as the old thermostat housing has hoses to both the manifolds and the risers on the log setup. The GILs have the thermostat hoses to the manifolds only and the water passes thru to the risers from a transfer/jumper hose, right? I'm wondering if I will need a new alternator bracket too? I guess I'll see.

Picked them up the other day, they were NOS in the box. Looks to be a complete kit. Also included were the gaskets and all the 4" hose I will need. And a bracket I believe is a shift cable bracket (#0906112). Also came with the 2 stainless steel "Y" fittings used to plumb a 4-port thermostat housing down to 2 hoses for water outlet to the exhaust manifold connections. Not sure if I will use these or change the thermostat housing completely. Changing from the old mercruiser log manifolds to these I will need to source a water separator bracket and an alternator bracket.

https://cimg6.ibsrv.net/gimg/www.off...2dd8fdc3bd.jpg

Ok, getting ready to start this project and swap the manifolds... Looking for some advice from those that have done the swap from logs to center type or performance type manifolds...

Should I keep the old 4-port thermostat housing and use the y connectors so it outputs to 2 hoses or should I just buy a new thermostat housing? If purchasing new what thermostat housing do you guys recommend?

I need to relocate the starter relay, does anyone make a bracket to do this so its not attached to the exhaust manifold?

I need to get a bracket for the alternator as the old one attached to the front of the exhaust manifold. Anyone have any ideas whats out there?

Also need to get a bracket for the fuel filter / water separator as the old one attached to the front of the exhaust manifold. Anyone have any ideas whats out there for this?

what out drive do you have??

Alpha 1... down the road I'd like to upgrade to a bravo 1.

do you no anyone that has sb gill exhaust thanks
 

cant find anything did you use the gill thanks tom

looking for gill small block manifolds .can anyone help

Use the Y with the 4 port tstat housing. Works great.

The newer 2 port can cause issues when the internal bypass corrodes more open or more closed because the Alpha pump doesn’t pump near the water volume as the Bravo. This is also why there is a special 2 port for the Alpha. It is cast with Name Alpha on top. Do not think of using the other one.

smallblock gill
 

looking to by a set not having any luck