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post #1 of (permalink) Old 08-27-2001, 12:48 PM Thread Starter
 
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big block question

I'm in the middle of rebuilding my 350, but have come across a decent deal on a 454. I found an adapter to bolt it up to my 350 trans. and figure on changing out the motor mounts. My problem is I haven't done this swap before and was wondering if there is a bunch of stuff I'm over looking that could pose major problems.
I appreciate any input, I need all the help I can get.

Hey Scooby, If you're reading this, did you get the '72?

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post #2 of (permalink) Old 08-27-2001, 01:05 PM
 
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Re: big block question

<font face="Comic Sans MS">An adapter to bolt a 454 to a TH350??? I'm not sure why you need an adapter... I could have sworn that a big block will bolt up to the same transmissions the small block would and vice versa... </font>

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post #3 of (permalink) Old 08-27-2001, 02:11 PM
 
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Re: big block question

I dont think you will need an adaptor.
But a 454 will tearup a TH350, thats why Chevrolet never put them behind a bigblock. It will last for awhile and when it goes put a TH400 in it's place.

No deal YET on the 72[img]/wwwthreads_images/icons/mad.gif[/img], it's getting close though!
He went to California for the weekend so I didn't get a chance.
It's kinda a weird deal, the truck is not really for sale he built it for his daughter, but she dosnt want it, or like it and says its a "gas hog" (350/TH350)
I feel kinda like when my 5yr old daughter is sleeping with her favorite toy and I have to slip it out of her hands without waking her up [img]/wwwthreads_images/icons/blush.gif[/img][img]/wwwthreads_images/icons/shocked.gif[/img]
If I move "too fast" he will "wake up", and realize what he is doing.
I wanted to take a picture to post of it this weekend, but I dont want to get my hopes up too much.

[img]/wwwthreads_images/icons/blush.gif[/img] I even had my wife to talk to his wife about it this morning while they walked the kids down to the school bus[img]/wwwthreads_images/icons/blush.gif[/img] I know I should be ashamed, but what can I say.. I want the thing![img]/wwwthreads_images/icons/smile.gif[/img]
By the way neither of these women like the truck (and I know his wife would like it gone[img]/wwwthreads_images/icons/wink.gif[/img])

Scooby Dooby Doo !!!
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post #4 of (permalink) Old 08-27-2001, 02:31 PM
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Re: big block question

If you presently have a chevy 350 you don't need to change your motor mounts or use an adapter for the transmission. you will need the flywheel for the 454, as they require a specially balanced flywheel.the motor mounts will bolt on to the engine right off the small block and the bellhousing pattern is the same. If it's a buick, olds, or pontiac 350 the bell pattern is different and the mounts won't fit.

post #5 of (permalink) Old 08-27-2001, 03:11 PM
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Re: big block question

Exactly on what 95 silverado said. And a th350 will take quite a bit of abuse. If you are going to do lots of hard stuff you probably wana upgrade or at lease get it rebuilt with a kit fron transgo to eliminate the crossleak that kills 350's and 400's(I'd get one installed if you get a 400 too)

83 1/2ton 350 700r4 soon to be bigger
post #6 of (permalink) Old 08-27-2001, 03:23 PM Thread Starter
 
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Re: big block question

I must be drunk. Dont ask what I was thinking about the tranny thing. That was one of the reasons for wanting to attempt the swap because it will bolt right up. (dumb ass!)

Thanks for the input though.

Hey Scooby, no shame no shame. Just make'n it happen. Going about it right though getting the wifes on you're side. Good luck







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post #7 of (permalink) Old 08-27-2001, 04:15 PM
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Re: big block question

About the motor mounts.....The 350 ones arn't going to work for ya. Actually 2/3's of the mount will work but the "cup" that bolts to the block is to large from the 350. You will have to get the "cup" off the 454 because the distance from the center pivoting bolt to the block is shorter and there making up for the extra width of the 454. I just put my BBC on to my puller frame last week and thought I could just use the mounds off the 350 like everyone said but I went and put it on and the engine wasn't nearly sitting in the frame rails like it should. So I went and got that "cup" off a BBC and bolted everything back on and dropped the motor down and it fit perfect.

Good luck...Ryan

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post #8 of (permalink) Old 08-27-2001, 04:26 PM
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Re: big block question

unless you got the cash, i wouldnt worry about your transmission very much. As long as your fluid isnt burnt up pr anything you shouldnt have any problems with it. Ive seen a 350 trans haul 11 facecords of wood (alot) and have no problems to this day. Doesnt mean it wont blow out, but its not inevitable.

-Ryan

post #9 of (permalink) Old 08-27-2001, 05:01 PM Thread Starter
 
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Re: big block question

It sounds like I'm getting in over my head here. I'm gonna have help with the swap, but I cant ask the dude to do it all. He's one of my neighbors that I did some electrical work for in trade.(good drink'n buddy too) I can't ask him to do any more for me than I did for him even though he would. Plus I wouldn't learn for my self if he did it.

The trans strength I wasn't too worried about for now. I keep it cool and hell, it's eaysier to get an upgrade by my wife if the old tranny is trashed.

Hey all, thanks again for the input

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post #10 of (permalink) Old 08-27-2001, 09:54 PM
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Re: big block question

Thanks, you answered a question I have been wondering about concerning swapping in a big block for a long time too. You didn't mention whether or not you used the plate/bracket that goes between the cup and the block for the tranny strut rod. Did you use that too?

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