Upgrading 1967 Sportwagon to GS400 engine, Suspension?

Some of you may have seen my earlier posts that I am replacing the 340 V8 in my 1967 Sportwagon to a GS clone. Major upgrade is swapping the 340 V8 with a 1967 GS 400 engine now being rebuilt. My question revolve around the following:

• Do I need to upgrade front suspension IE: springs/shocks to GS springs because of the 400 engine? I would think the 400 does not weigh that much more than the 340. The wagon clearly weighs more than a 2 door coupe or convertible so maybe the factory upgraded the suspension due to the weight? The car has factory A/C which I am keepingand not sure that extra A/C weight made a difference to the factory when building the suspension
• I am assuming the pulleys, A/C alternator brackets on the 340 work on the 400 but I may be in for a surprize?
• I want to add sway bars to the wagon, front and back. Comments, recommendations? Would think I have a set of upgraded rear springs due to the weight of the wagon and potential loads to be carried and this is a 3 seat or 7-8 passenger wagon.
• I want to install a GS dual exhaust system but the gas filler tube blocks the normal stock set up on the driver side. Will probably have to have something fabricated.
• Already have a 4 core radiator because of the A/C so I should be OK with the 400
• Need to check whether I have a 300 or 400 AT transmission behind the 340. I want to install the 400 and have one I can have rebuild if it is a 300 OEM in the car from the factory
• Are motor mounts for 340 the same as 400 mounts. I have a set of NOS 400 mounts and will probably use them.
• I am considering disk brakes on the front as I have that on both the 67 coupe and 67 convertible

Any recommendations/comments welcome.
Thanks

 

ttt

 

The frame pads for the 400 430 and 455 are the same. The 340 300 are different than the big blocks.
U are going to need to change those. The after market pada raise the engine up a lil bit which could hurt your breater clearance if u have a taller than stock intake.
The factory radiator is a decent unit as long as u have a good fan to pull air through it at lower speeds/rpm and a shroud is jist as equally important. Note that the small block shroud will interfere with the bigblock. Not sure
if wagon uses same length rear control arms as the coupe but if it does u can't go wrong with a set of factory boxed lowers and the affiliated sway bar that bolts to them!

 

Thanks Chris

 

67 gs frame pads are 1 year only and needed if you have NOS 67 on engine mounts. The engine mounts will have the nut welded to the engine mount.

If you need 67 only factory frame pads I have a set. If you buy TA aftermarket frame pads you will need the later motor mounts they sell or are avail for 68 and later big blocks. That raises the engine some.

If you go that route I will buy your NOS motor mounts for my 67 vert.

 

Chuck,

I believe the springs will be different for a 400 than what you have in the car. I would have to look at the part numbers in a parts book but considering that AC cars were sprung differently than non-AC cars due to the weight of the AC system alone, I think you will probably need to swap springs when changing to a Big Block.

I have a couple sets of springs from 1967 Big Block AC equipped GS 400s if you need them I also have AC pulleys if you need them. Lastly I have a Switch Pitch 400 and torque converter out of a 1967 Sport Wagon with correct tail shaft for your car, if you need one. Not sure if your car came with a SP 300 or 400 with a small block.

 

Don't forget the spare tire well on the passenger side. You may have to fab something for the dual exhaust for that as well. I'm planning the same swap but with a 455 and am looking at a side exhaust ahead of the rear wheels.

 

Thanks Stacey, I would be interested in the springs if they show up different in your parts book if you have time to look. We will be pulling the 340 in a couple of weeks and I will know more about the pulleys on the 340 and wil compare them to the pulleys on the GS400 coupe I have. If they are not the same then I am interested in your pulleys. I do have a SP 400 out of a GS400 that came with the engine I am rebuilding. I need to get the car on a lift and check the transmission in it. I am under the impression the 340 4 barrel in the Sportwagon came with a SP400. I will be in touch in a couple of weeks.

Chuck

 

Excellent point about the spare tire well Bill, I had not thought about that. I need to get the car on a lift and study the potential exhaust routing. I too have thought about the exhaust ahead of the rear wheels.

thanks
Chuck

 

Ed, you have a PM,
Thanks
Chuck

 

Hi Chuck, I don't have any new pms. Thanks

 

Well, I just tried again, lets see if this one gets to you. Let me know by PM

thanks
Chuck

 

Why not just have the exhaust exit just behind the rear tires ala Chevy Chevelle SS cars. Isn't that where the exhaust exits now on your car? That would look more like a factory installation.

 

Like this:

I was thinking to avoid the over the axle pipe and give it a more contemporary look. I also like the factory sleeper look, although headers and a Magnaflow muffler may give it away,:laugh:.

 

I have heard that the trick setup to use on our Sporty's is to use the GN Over-axle tubes that exit just behind the rear wheels. You should have a double-hump dual exhaust trans cross member

 

You guys have given me some interesting ideas which I will check out when I put the Sportwagon on my lift.

Thanks,

 

Chuck, my '65 Sportwagon has duals exiting on the sides/behind the wheels, as pictured on the aqua wagon above. Works/looks great.

 

Chuck I replied tp your pm. Ed

 

I will address the sway bars, I upgraded my front to a 1 1/4" and installed a rear with 1"
the rear lower trailing arms should either be boxed in or steel spacer tubes used so they don't collapse when bolting the sway bar on.
I also replaces all the bushings and steering linkage with MOOG. I heard the poly bushings ect. are real stiff.
I wanted a like new ride with less sway.

box in kit OPGI or TPP weld in and powder coat

 

Boxing the rears adds a lot of strength vs spacer tubes - and the kits are an easy job. I would go with the box kit.