73-87 exhaust manifold

[GRSEMONKY]

Has anyone modified their frame to use the truck manifold's that come on the 5.3 . I was looking at the swap TRUCKS did on the 72 and they bent and notched the frame on the passenger side to use the stock truck headers just want to know if this can be done on the 76. Trying to keep cost down since I have the complete exhaust off a suburban to use in my swap.

[dayj1]

Originally Posted by GRSEMONKY

Has anyone modified their frame to use the truck manifold's that come on the 5.3 . I was looking at the swap TRUCKS did on the 72 and they bent and notched the frame on the passenger side to use the stock truck headers just want to know if this can be done on the 76. Trying to keep cost down since I have the complete exhaust off a suburban to use in my swap.

I notched the frame on an '86 for passenger side manifold clearance. It doesn't take much. Maybe 1/2".

[BR3W CITY]

It'll also depend a bit if the manifold were the EGR ones or not. The EGR manifolds have an extra hump on the outer primary of one manifold. They all will fit flipped backwards with a turbo.

[GRSEMONKY]

Originally Posted by BR3W CITY

It'll also depend a bit if the manifold were the EGR ones or not. The EGR manifolds have an extra hump on the outer primary of one manifold. They all will fit flipped backwards with a turbo.

My manifolds do have the egr port. Turbo would be nice but this is a budget build...at least for now

[dayj1]

Originally Posted by GRSEMONKY

My manifolds do have the egr port. Turbo would be nice but this is a budget build...at least for now

On my '86, the area that needed to be clearanced was for the flange of the exhaust manifold (where it bolts to the down pipe). EGR clearance wasn't an issue for me, but it probably depends on the type of mount and the exact position of the engine.

[GRSEMONKY]

I'm using LSX INOVATIOS adapter plates. The ones that have the 3 different positions.

[BR3W CITY]

Originally Posted by GRSEMONKY

I'm using LSX INOVATIOS adapter plates. The ones that have the 3 different positions.

Thats doesn't really tell us much. There are like 50 companies doing versions of adapter plates, perches, and mounts, all of which are very very similar.

The EGR is in the way of the edge of the frame rail, at least in the earlier trucks...IF your engine is sitting more towards the front set of perch holes (again, exact position will be relative). If your far enough back, the frame widens slightly and the EGR can clear. The trimming is minimal if needed.

As was also mentioned the flange can be in the way, but this again depends on how far back the engine sits. If you were to run Vbands instead of the 3 bolt flanges, the is no clearance problem. In some cases, you don't have to trim...but it requires using a REALLY odd combo of wrenches and getting a gasket in place is nearly impossible since its in between the lips of the frame rail.

From my experience, if your running a 4l80e, the very outer corner of the bellhousing ear on one side or the other may interfere slightly with the exhaust hardware. This was the case with my TBSS's. It only requires a minor shaving of the cast aluminum ear, which doesn't hurt anything.

[Houston Ben]

I used DD mounts and had to bend the frame like on trucks on the passenger side. Works fine.