Newb Motor Swap Question #1

[arturo7]

Below is a pic of my 59 panel engine compartment. I plan to install in a 350 and a T5 tranny. I assume that it's not as simple as dropping everything in. New crossmembers will need to be installed, right?

One of these http://www.classicparts.com/1947-59-...ctinfo/79-405/

And one of these http://www.classicparts.com/1941-59-...ctinfo/79-505/

Are there other alternatives?

Thanks

[Wrenchbender Ret]

You do not need the first one if you use the original type v-8 engine mounts. If it came with a 6 cyl. you can get the complete changeover kit. You use a cast iron bell houseing that fits on the crossmember that is in it. Put the second crossmember under the rear of the trans to support it.

[mr48chev]

I'd say wrenchbender nailed it. the two large holes in the crossmember are where your rear motor mounts fit when you use a cast iron bellhousing. the factory front motormounts should fit in the rear most holes in the front crossmember. With the aluminum case t-5 a crossmember under the back of the trans isn't a bad idea either.
Make sure the bellhousing has the correct smaller diameter hole for the bearing retainer to fit in as later belhousings had a larger hole and you have to use a spacer ring.

[arturo7]

these? http://www.classicparts.com/1955-59-...ctinfo/79-375/


go on the back holes of this crossmember?



and

The bell housing mounts here?

Originally Posted by Wrenchbender Ret

If it came with a 6 cyl. you can get the complete changeover kit.

The vehicle did not have motor when I bought it. How can I determine which motor was in it?

Originally Posted by Wrenchbender Ret

You use a cast iron bell houseing that fits on the crossmember that is in it.

How do I determine which is the correct bell housing. Will the choice of transmission affect this as well?

[arturo7]

Originally Posted by Wrenchbender Ret

Put the second crossmember under the rear of the trans to support it.

How is the position of this crossmember determined?

Originally Posted by mr48chev

With the aluminum case t-5 a crossmember under the back of the trans isn't a bad idea either.

The tranny crossover is not absolutely necessary? What factors into the decision to use it?

[arturo7]

What is the purpose of these side mounts?

[OrrieG]

Factory v-8 had two front mounts that riveted to the front crossmember, it did not use the rear holes, that will be evident when you bolt in the engine block and bellhousing for a trial fit. The two side plates are left over from someone elses engine transplant, but it does not appear to be for a Chevy. Something with side mounts, may have had a homemade sling type too. Its late tomorrow I will scan the v8 mounts out of the factory assembly manual.

[arturo7]

Orrie, I have the manual, just tell me where to look. Is it 6-2.00?

[OrrieG]

RPO 408 sheet 12.00 near the back. That whole section is the V8 option. I already scanned it so it's attached. Here is a picture of the stock front mount I fabricated using the stock frame holes.

[arturo7]

Thanks, O. You wouldn't happen to have a sketch of that fabricated mount, would ya? Or is that something that should be done for each specific installation?



These would still be used, sans the bottom bracket?

http://www.classicparts.com/1955-59-...ctinfo/79-375/

[mr48chev]

That truck most likely came from the factory with a six in it but I'd have to think that a large percentage did.

There are several ways you could go on the front mounts including getting the original style brackets, using one of the universal under the engine mounts or fabbing your own mounts.

It doesn't absolutely have to have the rear mount on the trans if you use the bellhousing mounts as stock tri 5 trucks don't but with that aluminum case and the length I'd think that a mount at the back of the trans would give a bit of additional support and security. Again one of the universal aftermarket crossmembers would work or again a guy could fab something.

On the side mounts that are in it, someone may have had a V8 in it with a Hurst style mount that is often used to put a small block Chev in early V8 Fords. The spacing looks pretty close for that.
Here is a link that shows a Hurst mount http://www.oilnspeed.com/albums/v/sp...02mod.jpg.html You have to use your imagination a tad to see how it works.

[OrrieG]

Originally Posted by arturo7

Thanks, O. You wouldn't happen to have a sketch of that fabricated mount, would ya? Or is that something that should be done for each specific installation?

I can get some measurements and post them BUT my truck is 4wd. I located mine by installing the front axle, installing the engine SB, auto trans and transfer case using the stock 74 from drive line (pita to modify). I checked to make sure I had clearance for the distributor and heads then made up the mount. It looks close to where the stock one lands. I made a template out of plywood, you can do the same and move it around. Nice thing is if you keep the radiator in the stock 6 location there is plenty of room to move it forward a little. Watch that the pan doesnt interfere with the axle or tie rod.

Mr. 48, I had a mount like that once and was told it came out of an early Corvette.

[arturo7]

Originally Posted by mr48chev

There are several ways you could go on the front mounts including getting the original style brackets, using one of the universal under the engine mounts or fabbing your own mounts.

Originally Posted by OrrieG

I can get some measurements and post them BUT my truck is 4wd. I located mine by installing the front axle...

Just when I thought I was getting a handle on it, I'm back in the weeds... So it's not a cut and dried "the motor goes here" kinda thing?

I'll be doing the work in at my buddy's shop. Thus relying on his goodwill and fork truck to get the job done. It is necessary to futz around with the motor placement then fabricate custom mounts? I was thinking I could could just bolt on the mounts then have him drop the in motor...

[arturo7]

Just spent several hours doing my homework on the topic. Seems the more I read, the dumber I get... Looks like I'm going at this backwards and there is no hope of an off the shelf solution.

I want to keep the rear crossmember and use it to mount the bell housing. I guess the question is this:

Is there a bell housing that
A) uses the mounting holes on the existing rear crossmember
B) is compatible with either the NV3500 or 4500 (T-5 ruled out)
C) allows for clearance between the 350's distributor and the firewall.

Does anyone know where I can find dimensional drawings of GM bell housings?



EDIT: Guess I should say that I don't want to remove the rear crossmember. Being able to use it would be a bonus.

[1project2many]

I just spent half an hour typing a response and you go and change course while I'm typing.

AFAIK the bellhousing for that trans is an integral, cast in part. That trans is intended to work with a rear crossmember.

Distributor clearance is set by engine position, of course, which will be determined by where you set the engine. A simple procedure to get everything close to right is to get a bellhousing from the 55 - 63 period. It can be car, truck, or aftermarket. Attach your engine to the bellhousing and set it in place in the truck. Fabricate front mounts. Remove engine, separate OEM style bellhousing, then install NV3500 and re-install in truck. Fabricate rear crossmember.

NV3500 issues: No speedometer cable connection. Longer than stock trans (may require driveshaft modifications). Shifter is positioned rearward from stock. Rear yoke may fit turbo 400 applications. Sensitive to poor maintenance. Hydraulic clutch will require hydraulic master cylinder installation.

I think you're looking for an "overdrive" to keep RPM down on the highway. But the answer with the least work in cost and effort is likely to be a little different. A 350 makes plenty of low end power and I don't think you're going to be hauling heavy cargo. If an automatic's out of the question then consider using an SM465 four speed trans, an easy bolt in with the 55-63 bellhousing, and a numerically lower rear gear plus a narrow 16" tire (215/75R16). IIRC a Nova or Camaro rear from the 70's through 81 can be installed easily. They can be found with 2.73 and 3.08 gears which will bring rpm down on the highway, just like a 5 speed. The more modifying you do the harder it is to get the right parts when things break.

One other note. Make sure your block has provisions for front mounts if that's the route you're going. Some don't.

[OrrieG]

The bellhousing you want is shown below. It is cast iron and has the mounting pads shown circled in red. You need to locate the bellhousing and engine and figure out the mounts. There are at least three builds here that come to mind where folks ordered or built mounts then when they dropped in the engine, oops to high, low or close to the firewall.

[arturo7]

Originally Posted by 1project2many

I just spent half an hour typing a response and you go and change course while I'm typing.

Did you delete it? I may have changed again since my last post...

[arturo7]

Originally Posted by 1project2many

I think you're looking for an "overdrive" to keep RPM down on the highway. But the answer with the least work in cost and effort is likely to be a little different. A 350 makes plenty of low end power and I don't think you're going to be hauling heavy cargo.

You are correct, sir. I do want to keep the RPMs down. But, I also would like to have hauling/trailering capability. This was the reason for moving away from the T-5.



But then again, with every article or thread I read, I'm flip flopping feel like a teenage girl deciding on a prom dress.

[arturo7]

Originally Posted by OrrieG

The bellhousing you want is shown below. It is cast iron and has the mounting pads shown circled in red. You need to locate the bellhousing and engine and figure out the mounts. There are at least three builds here that come to mind where folks ordered or built mounts then when they dropped in the engine, oops to high, low or close to the firewall.

This is the 55-63 unit? Do you happen to know the model number? Maybe I can find some dimensions on line.

[arturo7]

Hmmm... now you've got me thinking, O.

Maybe an SM420? 1st gear is rather granny-ish and it's quite stout. Will this fit into the 55-63 bell?

Pair that with, dare I say, a Ford 9" for gearing flexibility.

Of course, by noon tomorrow I'll probably think it;s a bad idea...

[1project2many]

The SM420 is the original transmission. It will fit your truck like it was made to be there. The SM465 is the later transmission, started in '69. I recommended it because it may be easier to locate than the 420. Both transmissions were pretty rugged for daily use and they're a virtually trouble free swap in our old trucks so you could start with the 465 and if you stumbled across a 420 you'd have a good replacement.

There is a heavy duty 5 speed called an NVG4500 but it's not an easy install with the factory bellhousing. There are a lot of differences, some subtle and some not so subtle, between the front of that trans and the 420 / 465. The better route by far when installing this trans is to use a conversion bellhousing Originally the Chevrolet version wasn't equipped with a speedometer cable drive but the aftermarket has come up with solutions for that.

Note: Research this AM has revealed that guys are using a Dodge version of the NVG4500 and a plate that sandwiches between the factory GM bellhousing and the Dodge transmission. http://www.advanceadapters.com/products/pn-712550/ . You could keep your factory clutch linkage that way.

But the 4 speed and new rear axle is still probably the least expensive and shortest route to getting on the road. I think a 9" is a good choice if you re-drill the 5 lug axle to 6 lug. Around here I can find pickup truck axles for $200 to $400 in junkyards and less if I search Craigslist. The transmissions are almost throwaways since people seem to think 5 speed is the only way to go.

[54 jimmy]

just my two cents but if that trans crossmember is factory then it may be set in the factory location. if so all you need to do is get the bell bolted up to the motor. set the motor and bell in the truck. secure the bell to the crossmember with the stock mounting hardware. hold the front of the engine up. put an angle finder on the intake to get that angle right. check dissy clearence. then if all is good break out the cardboard,sharpie and sissors to make your front motormount tempelate. this is all depending on if the motor sits where you want it and if you are not going to lower the burb and how low you go with it for ground clearence. as for the tranny once the above is done you can bolt the trans up and make any other additional trans mounts you want depending on you trans choice. just use the kiss method. keep is simple stupid. hope this helps.

[beanyard]

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[beanyard]

One setup you might consider is the three speed with over drive and and 3:90 rear (all originally available. The rare part is the overdrive. I have this setup and it is very fun and functional.
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[mknittle]

Both sm420 and 465 are slow shifting truck trans missions. When I was a kid we were taking them out and useing m21muncie and borg warner t10 car 4 speeds.
I am running a sm 420 in my jeep for the low first gear.