Right side header is going to contact the AC lines. Be very careful bending them for clearance because they will most likely break. Of course if you don't have or don't care about the AC it isn't an issue.

 

Thanks for the heads-up. Do you have the same headers on your car?

 

No, my current car has stock manifolds.

Years ago I went through the 'cheap' header ordeal using the afterburner headers from Flowtech. They fit much better than any of the generic long tubes from Summit, Jegs, etc. Installed them on my wagon and another guys SS. The thread still exists but the pictures are long gone.

 

Looking at those jegs headers, I think the #1 primary is going to be close to the drivers side motor mount shell. Clearance from the pass. side frame rail may be tight too (esp. if motor mounts are worn).

I'll keep you guys posted on the install, stay tuned...

Looking forward to it.

 

Well looks like I'm SOL. The driver side header hits the oil cooler, more precisely the flange that holds the oil lines. You guys run into this before?

 

On the wagon, I ditched the oil cooler and went with a regular oil filter adapter on the block. The headers are still pretty close and I can only run the short filter. But, I also have a bypass filter installed, so filtration is not an issue.

 

The adapter was from a core engine at the shop, but it looks like GM used the same adapter from about 1968 until 2000, so finding a salvage yard part should be pretty easy. If not, here is a cheap one from Summit-

Summit Racing SUM-120115 Summit Racing™ Oil Filter Adapters | Summit Racing

Free Shipping - Summit Racing™ Oil Filter Adapters with qualifying orders of $99. Shop Oil Filter Adapters at Summit Racing.

www.summitracing.com

 

Would a 4.3 V6 adapter also work?

 

I believe so- Rock Auto shows the same Melling part for an Astro van 4.3 as a 1/2 ton truck with a 350.

 

Update: almost have the driver side header in, #1 primary is about 1/8" from engine side of engine mount.
Header hits the frame stiffener between k-member and side rail. I didn't expect these to fit perfectly, but they're listed as fitting <1990 B-cars, so shouldn't be interference with the frame.
I guess I'll bend/hammer it to get clearance.

 

The ordeal part was trying out other brands for the most part. The afterburner header fit like a glove, cleared everything and my Dynomax pipes hooked up to the headers perfectly.

 

Yes there is a gasket. One of the HELP items at the parts store had the gasket in a kit for a variety of applications.

 

To clarify, the 1968 and up " typical sb chev" adapter doesn't a gasket.


LT1 cooler adapter does,
LT1 non cooler ofset adapter, 98 % sure it does

One thing to remember, any gasket hanging inboard of the adapters, is on the "clean side" If unsupported extra comes loose, it goes striaght into the bearings.

 

I got the driver side header in. The passenger side just hits a break line on the frame rail when bolted down. I think this is why:

When I unscrewed the nut of bolt indicated above, I was able to easily pull bolt out by hand without lifting the engine.
Bad engine mount?
I don't know if this is in the scope of this thread, but Rockauto lists an AC Delco mount for $87 & a Pioneer (2nd most expensive) mount for $6. Is the huge premium for Delco mount worth it?
Do both motor mounts have to be disconnected in order to lift engine enough to get only one out?
Anybody have experience with polyurethane engine mounts? How objectionable is the added vibration they impart? (please keep in mind car already has polyurethane body mounts)

Thanks

 

The fact the bokt slides out is not an indicator of mount condition
There are tabs that support the weight.
The fact the bracket is touching the cross member DOES .
That mount is sooooo done!!

Nothing wrong with the cheapo mounts.
I have them but I do recommend filling the voids with urethane, like windshield urethane.

If you choose the poly mount route and they are not readily available, I I have a set here in BC

 

I picked up some urethane engine/trans mounts on a close-out sale and used them when the engine went back into the wagon. Can't say of they transfer more vibration than OEM or not because the original ones were like yours with the upper mount resting on the frame and was harsh.

 

I got a pinhole in one of the AC lines while bending it for clearance.
Guess I need new AC lines, any suggestions?

 

I bought a new set of lines from Carquest via work and the turned out just fine. First I bought a super cheap set from Rock Auto and do no recommend anyone else does. The low side fitting snapped right off when I connected the recovery machine to it.

Of course since you need to make custom bends due to the headers I would just have some custom lines made. We make them at work and can obtain special fittings and such. Most any semi truck repair facility should have the same abilities.

 

Without having a drawing, could a truck shop use my clearanced (but cracked) lines as a guide?

 

They make adapters that will connect to the compressor and then connect new lines to it. However I have never looked into it and they may not be available for our exact compressor. There are so many different ones it isn’t funny. The shops you went to either know there isn’t or didn’t want to research. My experience leans towards the latter, lol.

The factory lines can be “massaged” enough to work fine because I accomplished it on an Impala I put headers on. I just had to be patient and work slowly. On my car I didn’t care because the AC was dead. I don’t bother with it on my current wagon because the last thing I want to lose in central Florida is my AC.

 

Driver side header is rather low:

Yeah, should've bought the tri-Y's.

 

Baa, thats nuthin

 

Headers are installed. It was painful.
I think these are dimensionally identical (?) to Summit 9001.
Require bending of AC lines. I have SPC A-arms, running stock ones would most likely cause chafing of AC line, especially with camber shims.
trimming frame braces, moving left front brake line a bit. Motor mounts need to be in good condition.
I hacked up some tin to shield things from heat, just in case (AC lines, connector on PS pump, starter, 02 sensor wiring, knock sensor wiring). I made up some over-valve -cover spark plug wires. I rerouted starter and R knock sensor wiring to go in front of and under engine mount
As seen in photos above, driver side header is lower than passenger side.
One good thing is that factory cross-member doesn't need modification, provided you don't need cats (pipe needs to be bent around it). Photos to follow

 

I bought a set of these headers, and they are a royal PITA to install on an LO5 They hit the front suspension braces, and the rear bolts on each pipe on both sides, except the rear on the driver's side are nearly impossible to tighten. The design is easy for the manufacturer to make for a more friendly installation. Narrow them at the bottom by 1/2 inch, and make clearance for the bolts at all stations. I am tempted to design my own headers and produce them.