Tubular engine mount crossmember??

[Matt_50]

Ok, so my big goal is to have my engine and trans installed by the end of the month. In fact I'm planning on the last Sunday of the month. We will see how it goes...

So I already ordered a tubular style crossmember for a 350 engine. I got it from Performance Online. I'm assuming it will need trimming and its a bolt or weld on type. Seems easy enough right? I've never used one of these so I'm curious about something.

First picture is the whole thing with the ends slipped on. Second picture shows a close up of one of the ends where it slips onto the center part.

See the gap? It's a loose fit.

Is this right? Is this because the frame isn't square?

Can I weld that gap or should I drill holes and run bolts through the ends?

[joedoh]

I will be putting one of these in my S10 chassis this week or early next (guy is coming to pick up my most recent truck or I would do it tomorrow)

I plan to NOT use anything like the ends you have and will just weld the yube to the frame. in my opinion those ends are suitable for a trans crossmember which is just the third point of a triple mount and doesnt need to handle torque, thats what the motor mounts do.

alternatively you could weld it or run a bolt through it, but why would you need a removable engine crossmember? removable trans mount, sure.

[Matt_50]

Well...i suppose I could weld the tube to the frame. I wasn't going to use the bolts, I'm thinking just weld the ends to the frame... just looked sturdier from pics I'd seen. I'm paranoid lol

So if I keep the ends and weld them...the gap you see in the two tubes...the crossmember tube and end collar tube.... shouldn't be a problem right?

[joedoh]

those ends are mostly for people who dont have a welder, so the crossmember can be bolted in. if you have a welder, you dont really need the ends. if you just want to use them, make sure you weld them on really well and I would even drill a couple holes and plug weld the ends to the crossmember.

[Matt_50]

My welding skills are not the best, or at least I'm not experienced enough to trust myself yet lol at least not with my engine.

As for these mounts, i was concerned over the loose fit. But I guess a good welder could fill the gap right?

[joedoh]

I am sorry for confusing you, what I am saying is, adding an extra step is a point of failure. if you are going to weld the end to the tube, you can weld the tube to the frame and eliminate a step.

if you are planning on bolting the crossmember in, that is different. if that is what you are doing, yes, weld the ends on as best you can, and plug weld them in a couple spots by drilling a couple holes through the end piece and then filling them back with weld.

if you arent bolting it in, weld it in and skip the ends. its not "sturdier" with the ends welded on then welded to the frame, except maybe where the flat flange will work as a doubler

[Matt_50]

Ok I see, either bolt to frame AND run bolts through the tube ends through the crossmember to or prevent twisting and movement. OR get someone to weld it all in for me.

If it's bolted... For the bolts to prevent movement...should I have horizontal and vertical bolts because the two tubes are not a tight fit? Are there any threads of anyone doing a bolt in?

For either way I go... I want to double check my facts.

When installing engine... do I get the crossmember as low in the rails as I can and just far back enough to be able to pull distributor? What is the gap goal between firewall and distributor cap?...350 engine with th350 trans

[Matt_50]

Also... I'm assuming the crossmember needs bend towards front of truck right? For pan removal. With the mounts level the tube bends away instead of directly under. See pic.

[yossarian19]

Let me guess - CPP parts?
Where the mounts thru bolt to the cross member, mine was too wide / mounts didn't fit, the LS oil pan didn't clear & the ends were sloppy, too.

[Matt_50]

Performance online. Looks like once I tighten rubber mounts they would be right. I've never used one of these... so I'm not sure which way the crossmember needs to go. I'm now wondering if it goes towards back.

[dsraven]

it would be easy to bolt some motor mounts on to the engine and then bolt the crossmember up to the mounts to see which way the oil pan clears the best. also, do you have a dropped axle? make sure you leave room for suspension to bottom out. assuming you have an assembled engine?

[Matt_50]

Yea... I think I'm over thinking the little stuff.


Bolt to engine, lower onto frame. Position it where I can still pull pan off.

Find the sweet spot...possibly trim the tubular crossmember if needed. Get just close enough to firewall to pull distributor.

My floor is flat and I've been told by multiple people my th350 should clear no problem. Any naysayers?

I'm going to measure my pinion angle from donor. Measure back of trans and the axle and try to get same angle. Sound right? My carburetor should be level correct?

This crossmember can be bolted... then drill holes and run bolts through to keep it from twisting and turning.

Best bet is to get a buddy to weld it.


Everything sound right?

[Dan in Pasadena]

When I took the 283 out of my truck the end had been welded onto the tubular portion. The entire cross member was bolted to the frame flanges.

[joedoh]

I got mine from speedway and the welds are gorgeous, best 75 bucks I have spent.

I got mine welded in. I had the original mounts to measure from, so 22" off the floor to the front hole (dont use this dimension, thats just how I did it) and 10 1/4" rearward move. it sat a little over the frame in position so I built some close out pieces and welded those in too.

IMG_7415 by Joe Doh, on Flickr

IMG_7418 by Joe Doh, on Flickr


you want a 4 degree down angle, your intake is set this way and so is the trans pan. you may not be able to remove the pan with it in place. you will also want to offset to the passenger side for steering clearance! very important

[Matt_50]

Steering clearance... I swapped out my factory axle and suspension and bolted on a c10 front suspension. Going to use c10 power steering too. I think I've been told I might need to make a small notch in inner fender. Do I still need to move engine over?

I'm still reading up on pinion angles... If carb is level my trans will be at 4 degrees right? Or ill be close and can make little adjustments....

[joedoh]

gm usually offset the engine to the passenger side, so yes you probably will too. its usually a half to a full inch.

I havent messed with a carb in 20 years, EFI guy here. but I will tell you the motor needs a 4 degree down angle, if that sets the cab level then the answer is yes.

[Matt_50]

Huh... I'll measure off the frame of the donor, to make sure I get right offset.

My plan, and correct me if there is a better way...

Put donor on level ground.
Buy digital level/protractor. I think some have a magnet...
Put it on frame to make sure I'm level..
Put it on axle where u joints go..put on trans.. read off where yoke goes in?
Get angle on top of carb. Will this read the same as off trans? Should be 4 degrees too?

Then copy over to new truck... level ground etc...

[Matt_50]

This'll be my first time putting an engine in and not using the factory mounts. Using a different crossmember and having to find where to put it is probably pretty easy for a lot of you but I'm just paranoid I'll be off just enough to give me problems.

I'm thinking I'll bolt it in. Then after I know everything has clearance and its all at the right angles...then have a friend weld it in. Sound good? I had a guy send me a pic of his distributor actually touching his firewall and he said he only had 3 inches of space between the radiator.

Is that the amount of room I'm gonna have?

[joedoh]

dont worry, it can be scary but we are here to help! I havent ever tried to do it any other way, 4 degrees down angle and offset to the passenger side a little.

I like about a 1/2 inch at the dizzy. the trans pan I think ends up level.

you plan sounds right, go man go!

[mongocanfly]

keep in mind your trans yoke angle needs to match your pinion angle..trans down, pinion up...if your pinion angle is up 4deg then your trans yoke needs to be down 4deg..the numbers need to match.

[Matt_50]

Thanks guys. I hope it goes nice and smooth. I plan to put the engine and trans in as a unit... figured it would be better that way.

So 1/2 inch between distributor and firewall and that should be enough to pull it if needed?

I know it'll be a tight fit... Will my stock exhaust manifolds from my c10 donor be an issue? Keep in mind I'm not using original steering. How about my water pump and fan, need to be changed?

[dsraven]

some pics of your current state would be great.
if you have a bolt in c10 crossmember under the original frame did you really need the cross member? could you fab up some mounts that would put the engine in as if it were going into a c10 frame? possibly use the C10 brackets? could you drop the engine with mounts and trans bolted on in the frame, with no crossmember, then move things around until you get a quick mock up location, block it in position, then see if you can make some cardboard brackets for patterns to connect the dots over to the frame?
I know, sorta what you are doing except there will be a cross member over top of a cross member, correct?
like I said, a few pics would be great so we can see what you are working with.

[Matt_50]

I'll take some pics she i get home. The c10 suspension bolts in, but to get center in the fenders the crossmember is to far forward to use c10 mounts for the engine. So yes there I'm using a 2nd crossmember, but it'll be farther back from the c10 one. There wouldn't be any room for radiator if I used the c10 mounts.

First pic is mine. 2nd pic if you can make it out is a picture I found of someone doing a similar install. Used a c10 front suspension and looks like a tubular crossmember.

Mocking up and making my own mounts sounds great but honestly, my welding skills are not that good for me to trust my mounts. That's why I bought what I bought and I can install myself and have it welded up whenever I can get someone over to do it if it needs welding.

[Jesse Z]

Originally Posted by Matt_50

As for these mounts, i was concerned over the loose fit. But I guess a good welder could fill the gap right?

The gap will actually BENEFIT the weld, making a recess for the bead rather than having it lay on top of the metal. All good welders grind a chamfer into edges before welding.

[Matt_50]

I think I'm over thinking to much. The weather is a little wet today so I might not actually get my rear axle bolted on, but it's ready to be so I should still be on track to have engine in by end of month.

Then we can see what else I can over think lol.