I was just able to purchase 8 GM 3836670 rod bolts for the later style 55-62 235 motor (3/8-24 at 2 1/4 length). Over the years I have heard that a rod bolt for a Ford 351 Cleveland may work as a replacement requiring just a little grinding on the head of the rod bolt to fit. Does anyone have any experience with this?

Also, and I know this is a long shot, would anyone happen to have either a new or used 351 Cleveland bolt that they would be willing to part with?

A similar mod is covered in my Stovebolt Performance Book but it features a Big Block Chevy rod bolt. You'll have to recondition the rods when changing the rod bolts so be prepared to do that additionally.

ARP still makes them:
Northern Auto Parts Curiously there are two different part numbers for a 351C - one for 80 bucks and another for 125. The latter is something called a WavLoc rod bolt.

Scott is your book available yet?

Stock49, I was hoping to avoid an out lay of 80-120 just to investigate, wife might not understand, lol. So that was why I was searching for a single.

Almost, just a little more photography.

Then I will anxiously await its publication.

Given any thought on the GMC lower therm housing I sent you?

Yes, i'm fixing to get some more of my new patterns cast.

Tremendous! It will be really really nice to have an aluminum cast them housing with water outlet on driver side. Charlie Baker was tinkering with this years ago (I have one of his prototypes) but I never thought I would see the day!

Just scored a new foundry contact and am sending him one of my intake manifold patterns. I'm going to pick up another milling machine and production lathe on Friday.

mdonahue05,
Tom Langdon sells a New thermostat housing with a outlet on the drivers side. The ones I saw were cast steel. And reasonable in cost.

CNCDude,
Good luck on the new parts and machining them. It can be quite a task.

Thanks, I got my first batch of all 3 intake designs all machined and shipped and have found a foundry much closer to me. That's been my biggest hold up in getting my next wave of new patterns cast.

It does take a good foundry to work out all the details to end up with a great part.
My foundry just worked out those details on a few parts for me.

If he does, I don't see it but sometimes I can't find my own nose, lol.

Here it is.
Thermostat housing

How about that. Completely missed it. I am hoping Scott will pattern his with a built in spacer to move the housing away from the head by 1/2 to 5/8 to allow for easier removal of a traditional cast valve cover (offy, Fenton, nicson, etc.). If cast aluminum, can be polished up!

Langdon's has that covered too:
Aluminum Water Outlet Spacer

The spacer I knew about but thanks for looking that up for me. I have made spacers myself. They look fine but What would be really be nice is to be able to purchase a one piece aluminum lower therm housing with an outlet on the driver's side for manifold heat and a built in spacer. Then you would use just one gasket instead of two with the spacer and the housing could be polished.

Yes, my water outlet will be as mdonohue05 has described. It will be a completely new design original to that product, not a copy of what someone has already done.

With this design - how will the heater be plumbed in?

It will have a boss for inserting a pipe fitting to plumb the heater hose.

I guess I should have been more explicit. The plumbing question refers to routing and flow.

You're redesigning the thermostat housing to move that boss to the drivers side - ostensibly to make plumbing for intake heat easier. The housing is the source of hot coolant for the heater. Where does the water pump get plumbed into the intake thereby inducing flow?

The approach I took on my build was to have the water flow from front the back through the manifold:

The source of hot coolant is via a tee in the drain petcock on the back of the block:

Flow is induced by fitting a tee on the water pump inlet:


This creates two coolant loops that constantly flow regardless of whether the thermostat is open or closed. One is the stock heater hose loop. The second is depicted above.

Are you putting the heater and manifold one the same loop? Doesn't that result in a heater hose routed over the top of the valve cover?

There are fittings on each side of the lower housing similar to the GMC housing. So instead of having a tee at the water pump on the outside as you have, it branches inside the housing in a sense, one going to the heater and the other going to the intake and then re-entering the block at the port you have the petcock if they choose that type of routing. I don't think there is a need for two parallel routes, seems redundant and adds unnecessary parts and plumbing, as long as the water pump pulley is spinning the water will flow as long as a deadhead isn't created, and in this case it has an in and out just as yours is routed through the intake. The factory heater hoses don't go across the top of the valve cover, so there wont be a need to route them that way.

OK. Having bosses on both sides of the housing maintains the source for the stock heater hose loop. But running a line from the driver side of the thermostat housing (through the intake) to the block drain hole doesn't provide for any flow. When the thermostat is closed the water pump impeller is pressurizing the coolant in the block - pushing against the thermostat awaiting for it to open. A line running from the thermostat housing back to the block would be under equal pressure when the thermostat is closed - and subject to minimal if any flow when the thermostat opens.

The stock heater loop is attached to the inlet of the water pump for this reason.

Both water sources are still below the thermostat just as in your setup are both below it. They are seeing the same pressure in both examples.

I was contacted originally to design and develop this housing with one primary objective and that was to provide additional clearance between it and the front of the valve cover. Secondly, add additional bosses or ports to allow plumbing of the intake if the user so desired to use this method to heat the intake without having to add tee's or other unsightly and unnecessary clutter to an otherwise clean and sleek engine. It is up to the user to determine what philosophy they subscribe to, as to the best routing of lines and plumbing to complete the installation to suit them.

So the hot water moves from the therm housing driver's side port to my Clifford intake (built in chamber for hot water.). Exits the manifold and I bring mine back over the area where the spacer is and use a T (repro 60s corvette) to plumb it into the heater hose on the other side of the motor to the water pump return (heater hoses in stock configuration). That way I do not need to run my heater to get flow to the bottom of the manifold.

Tom Langdon walked me through this a good many years ago now when I first switched to pinto 5200 Holley/weber carbs. Used a 302 Gmc lower thermostat housing (which were a big pain to come by not too long ago). Made a big difference in drivability. I have plumbed my system that way ever since. Works like a charm.

If someone is willing to post a photo for me (have not figured out how to do that, lol) I can get you a photo of my current layout. It's always changing a little but this is the configuration I took to the trifive nationals in bowling green this past August. I was the only 6 powered car making runs down the dragstrip the entire weekend.

This is my son making his maiden voyage down the dragstrip in dads old high school car. 40 years I drove the car. This year I watched as my car went down the strip with out me, very strange feeling but the smile on my son's face after he came back was priceless.

https://youtu.be/lMVz66tyrKQ

Indeed. The gotcha of tapping into the heater loop for intake heat is avoiding the shut-off valve in the heater controls.

The plumbing has to address both form and function. The unpainted photos above were intended to be illustrative/instructive. Based on input from FTF I have since ditched the brass and re-plumbed in galvanized. Once painted it recedes into the background:

May I give you an alternative if you ever want a little bling. Aluminum fuel line. Bends beautifully, uses a 37 degree flare and associated AN hardware, polishes up easily. I used it the first round and liked the way it looked but went to the braided when I stepped up to the 38 mm webers (needed a regulator where I never ran one with the 32/36 Holley webers)

Btw, love the caw valve cover. I have one of those covers on my parts shelf. One of these days I will use it on something!