Thread: 1956 Chevy Engine Swap

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Howdy,

I'm brand new to the forum and would like to introduce myself and ask for some opinions. I checked out many hot rod forums before settling on this one. I like the very active participation in this forum, and you guys seem like your really on top of it around here.

Anyway, my latest project is a 1956 Chevy 150 2 dr post. She's a bone stock car as she sits with a 235 6 cylinder and 3 on the tree. I happen to have a nice little 283 V-8 and Muncie wide ratio tranny that I've been sitting on that I feel would be the perfect drive train for this car, which I would like to restore as a period correct early 60's hot rod.

I'm not concerned about making the car look like it originally came from the factory with the V8, I'm more concerned about functionality and cost. I have a lot of experience rebuilding, pulling and installing engines, but have never swapped from straight 6 to V-8. I also have a 42 x 26 4 bay work shop and I will be performing all of the work myself.

The 283 came out of a 64 Impala with a four speed. It's warmed over with 461 heads, Edelbrock performer, Carter AFB, roller rockers, etc. It already has the pressure plate and clutch which are new. I also have an aluminum bell housing, and shift fork setup for the Muncie as well as a hurst shifter.

My concerns are getting the positioning right of the motor (motor mounts, tranny mounts, etc.), getting the clutch setup properly, and getting the radiator setup properly. I'm sure there are plenty of snags I haven't thought of and I would very much like to have any and all opinions, recommendations, etc. Especially if any of you have done this very thing to a tri-five Chevy.

Thanks in advance.

T

The 283 has the front mount holes to use the stock '56 mounts. The 6-banger rad will work as is.

And you'll need to either change the bell housing to one with the side mounts like your stocker has, or get a crossmember kit (or if you're handy a '67-9 Camaro one adapts easily) for the transmissions rearward mount. Stock Z bar and other clutch linkage should work if you use factory mounts.

Footnote; some believe front engine mounts and rear crossmember puts too much span load on the bellhousing.

Hey thanks guys for the replies so far.

I didn't even realize that 283 had the mounting holes up front, but I double checked and it does! Wow, cool. That would certainly make things fast and easy if I just got the bell housing to use the existing tranny mounts.

Bob, could you or anyone else elaborate on the downside of using the stock mounts and the long span bell housing stress? I see where that might be a concern. Is that due simply to the weight of the motor, or is it magnified by higher horsepower engines?

I take it the tri-fives that came from the factory with V8's used the same mounts? Did they have inherent problems? I'm not looking to drag race this thing, more of just a fun cruiser with a nice rumble. I may have a little fun with it, but I don't plan on hammering it. Not yet. Future plans could see a big block and narrowed 9 inch, but not this phase.

This motor, as built, I'm guessing has maybe 250 - 275 hp? 283 bored .030, camel hump 461 heads, Carter AFB, Edelbrock Performer dual plane, the cam I'm not sure of, but it has a relatively smooth idle, very similar to my '64 Corvette's 327/300 hp motor.

With this new knowledge about the 283 mounting up to the stock mounts, I'm seriously leaning toward just finding an early correct bell housing and going that route. Any input on that guys? It would definitely be less of a PITA and less money I'm sure.

Thanks again for all of the help.

T

Like Bob said, I am one of those people who believe that you will crack the bellhouseing useing front mounts and a rear crossmember. Classic Chevy, as well as other companies ,I'm sure make bolt on side motor mounts to go with a rear crossmember. That said I use front mounts with mounts on my blowsheild . of course when you do that your trans hangs out in space but I have had no problems with breaking transmissions carlg

Orange-Crush,

I see what you're saying about having the tranny just hanging out back there.

I guess I still have a few questions. First, I understand the 283 will mount to the stock front mounts. So that's not a problem. However, will my Muncie mount up to a stock tri-five V8 bell housing? If so, I could just use the stock bell housing mounts as well? I'm assuming the bell housing on the 235 is different altogether.

Then, I could always just fabricate a simple brace to support the rear of the Muncie at it's mount if I felt it needed it. Or just buy one out of a catalog and weld or bolt it in place. That's how I think I'd like to go. Is this possible?

Thanks again for all the replies.

T

Originally posted by t-bonewilliams

I guess I still have a few questions. First, I understand the 283 will mount to the stock front mounts. So that's not a problem. However, will my Muncie mount up to a stock tri-five V8 bell housing? If so, I could just use the stock bell housing mounts as well? T

Here's the link for CPP lots of good info on the site even if just for reference; http://www.classicperform.com/5557STX.html

Your stock trans has been "just hanging out there" all it's life, so that's not an issue. As Crush intimated, using a rear crossmember with the front mounts is believed to put undue stress on the bellhousing and front of trans because of the long span. I'm not 100% convinced of that, but then I'm not real comfortable with it either. I've seen lots of aluminum case Muncies with the front mounting ears welded back on. Personally I've had lots of Muncies and never broke a case, so is it an inherent weakness, or sloppy installation that causes the breakage? I'd vote for the latter. If everything were torqued up correctly and maintained that way, you could probably get by with the front/rear mounts as long as you weren't really hammering it constantly. Or go the tri-5 V8 bellhousing route.

Just another note, but you may have already figured that out too, the V8 won't use the same mount location on the front as the six, there's another pair of holes in the crossmember further back for the V8.

Lakewood bellhousing is available with early chebby side mounts, kit 620-15800. Bellhousing is pricey but it is a real safety device.

mike in tucson

Bob,

Thanks for the tip on the second set of holes. That stands to reason since the block is shorter. I think I'm gonna use the stock tri-five front mounts, find a tri-five V8 Bell housing for the Muncie, and just use the stock tri-five rear mounts.

When I started the thread, I was unaware that the 283 had the capability of mounting up front on the stock mounts. So, I was prepared to buy the side motor mount kit, the rear transmission crossmember kit, etc. but could forsee problems getting all of that in and lined up with the clutch linkage and all of that.


Thanks to you all, I know I can run the stock radiator, the stock mounts, stock clutch linkeage, all I really need at this point is a stock bell housing for the stock rear mounts, and to possibly modify the drive shaft.

This is getting exciting!

Thanks so much for all of the great input!

T

Hey, thanks Mike!

T

Now that's a color combination I can warm up to!

Holy cow Bob!

That's awesome! I've wanted to see those stock colors in their glory! After seeing that photo, I'm gonna HAVE to repaint the stock colors!


Thanks so much!

T

That's what an ex-Solomon kid is here for!

Didnt a six have the radiator on the front of the core support and the V8 have the radiator on the back of the core support? Or am I just having a "senior moment"?

Originally posted by robot
Didnt a six have the radiator on the front of the core support and the V8 have the radiator on the back of the core support? Or am I just having a "senior moment"?

You is correct! Cheated alzhimer's again!!