What do you guys think about my not being able to box the motor mounts? The material is 3/16" and is twice the thickness of the frame rails and I've got really long surface area on three of the four. The fourth probably has 2 1/2" of surface area welded to the frame. This is not going to be a drag racer.
I am also not sure that everyone has the same vision when 'boxing' is mentioned. My guess is that most folks would like to see 'something' between the two vertical plates to resist any lateral deflection. I am in agreement with that line of thinking. Something as simple as a piece of the same 3/16 x 1½"-2" that fits between the verts and touches the frame. Weld all three contact points. .
Exactly! Keeping for to aft movement to an absolute minimum is key on any swap. It's every bit as important as limiting side to side movement.
It would be easier to gusset the front ones to the top of the frame. This would help with with fore and aft movement. They are offset from each other since the frame turns in towards the front. In order for the piece you suggest to be of maximum benefit in contributing to rigidity, it needs to be perpendicular to the faces of the two vertical uprights. They are not in the same plane, so it wouldn't significantly contribute to rigidity. Does that make sense? Or, do I need to take an overhead picture and post it?
Wouldn't hurt! Basically though, anything you do to limit for to aft movement is going to be an improvement. It ties everything together and makes the front of the car function more as a unit. Believe it or not, it also effects your suspension. Instead of allowing the forces of the up and down movement of the suspension to be absorbed in the fexabilities and movement of the engine, it keeps those forces isolated at the corners where the suspension can do it's job. Hell I just wrote that, and it confused the hell out of me, but it's got to do for now! Trust me on this one, stiffer is better!
Worth at least 1000 words. You'll have to also look at the first ones to get a good idea. I've got a solution worked out but it's not "pretty".
Yep, they are not sharing much for boxing! Perhaps a plate that is flat in the same plane as the top of the frame rail, inside both front and back? Make sure it doesn't trap water or parts, so maybe tilt it down to the inside just a little.
That will help a little, RSR. I think if I do that plus put a gusset to brace the front mount to the rail, I should be ok. Don't you think?
Okay, how about a triangular piece that drops from just below the bolt holes for the engine mount on the rears, down about an 1 1/2" back to the frame rail. Then do the same but to the front, for the front ears. Leave the inside corners on the front open for the brake lines to p*** through. Make sense? I've got to go pick a bunch of cactus needles out of my hands, ( my *****ly pears are having a bad day) I'll check back in a bit.
I'm not worried about the brake lines, they can go down near the bottom of the frame rail and they have to be re-done anyway. There is nothing to fasten the DS rear piece to. I think I'll do as RSR suggested and put a triangular piece (also called a gusset) fromt the front to the frame rail. If that don't hold it, I'll pay the consequences. Seriously, the main force is rotational torque. Not front to rear thrust........unless you have a wreck. In that case, what the heck. I'm probably done anyway.
Great thread, ive been wondering how hard it would be to put a sb mopar in an early Plymouth. Im wondering though couldnt you have used early a-body v8 manifolds? The drivers side is curved pretty good to go around the steering box in the tight 66 and back a-body engine bays. Of course the port sizes are a bit smaller but you could port them out, and those manifolds are much easier and cheaper to find.
They would work but the ports are considerably smaller. They also won't fit the 360 heads. The spacing is different. You MIGHT get a set of 360 manifolds to work but the steering column might still be a problem.
The spacing is the same, but the ports are just tiny in comparison to the 360. Rockable, do what you said, that will work just fine. Rodstreetrace came up with that answer as I was typing mine - basically the same, just said allot easier. I know he truely knows the ways of the Mopar as well... As far as suffering the consequences, Just rather see the cards stacked in your favor if the unavoidable happens. Hell, my car will go on the frame rack for the third time in it's career soon to fix the damage from this springs crunch.I've got a buddy that's on here who is a world cl*** fabricator, Elpolacko, and his shop slogan is, No kill Like Overkill! Words to live by.
I think he is refering to the port size. 340 and 360 exhaust ports in the heads are taller and wider then a 318 port. The 318 manifolds just barely cover the 340/360 ports, but if the 318 manifold has a questional top edge, there may be an exhaust leak, and you loose a lot of power with the 318 manifolds over the 340/360 manifolds. Also, many 360s have an extra emission port hole under the exhaust ports that the 340 and older 360 manifolds and the 318 manifolds don't cover. If you have the emission port holes you need to plug them to use older manifolds. Gene
I know the ports are smaller, just thinking of a cheaper solution to hard to find and expensive 340 manifolds, when all out performance isnt a must. Cant wait to see that 41 running around Nc.
I used 360 truck center dumps that I hand ported, then sent to Extrudehone over in California quite a few years ago. You might be able to do the same with the 318 manifolds as well. I do have a pair of those that I forgot about, if any body needs them, P.M. me.
Three Deuces used to have a sign in his shop that had a huge welding electrode attached to it. It said, "When in doubt, make it stout!" Words to live by.
I would fefitely box the mounts. Since they are only 3/16" , most tabs for motor mounts are 1/4"- 5/16'.
Nothing cooler on a small block than a set of 340 manifolds, they work very well too. Cost is an issue however, I sold a set back in the 90's for $300.00! You can buy them new for $900.00 http://www.accurateltd.com/340-Exhaust-Manifolds-Pair_p_9-162.html you might want to consider using one of these gaskets to keep from burning plug wires on the driver's side See if you can find a used one - new they are like $200.00
What a bunch of good MoPar info. Good to see the infected folks helping each other out, as it is hard to cure the M.P. disease. Looking good Rock. ~Sololobo~
About that firewall -- there's an excellent article in this months or last months (August?) Rod & Custom or Hot Rod mag, about re-working the firewall to get more room - they put a hemi in one, so that should give you tons of room for a small block.
Hey guys, I don't mean to hijack this thread, but tell me what you think. I have a complete set of the articles that Eric Peirce wrote on this subject for ROD ACTION magazine as it's editor. I have been in contact with him about reproducing them, which is a almost step by step for this swap. If I can get final clearance on this, any body want to see?
I'd like to see them. I'm planning on pulling a SBC 350/350 out of my '38 Chrysler and replacing it with a SBM (haven't found one yet)/727, so I'm reading everything I can find.
God bless you man, you are a hero! If I win the lottery I am going to buy a bunch of mopar rods with chivvys in them and swap in mopar power . . .
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