69 Chevelle 307/454 swap
Chris Jon Bergquist
My son has a 69 Chevelle and he wants to swap out the 307 small block
for a 454 big block. It has a Turbo 350 transmission. What do we need
for front motor mounts and will the 454 bolt up to the Turbo 350?
Thanks for your help.
Chris
Joe Wiles
them with new units. The engine will bolt up to the THD 350 with no problem.
I would replace the small flexplate with a larger diameter one. The 454 needs
the extra umph for starting. The only other thing you will need to do is
replace the front springs. The 454 weighs about 100 to 150 pounds more than
the 307. Good luck.
WILDMAN
J. Forbes
In article <53ar8m$7...@kocrsv08.delcoelect.com> Joe Wiles <jjw...@koasm010.delcoelect.com> writes:
>From: Joe Wiles <jjw...@koasm010.delcoelect.com>
>Subject: Re: 69 Chevelle 307/454 swap
>Date: 7 Oct 1996 11:58:14 GMT
> WILDMAN
And put in a new, heavy duty TH350 or a stock good used or rebuilt TH400. The
454 will smoke a used 307 spec th350 in no time. The 350 engine equipped
cars had more clutches in the tranny-the 307 equipped trannys were the same as
the 6 cyl trannys, with one fewer clutch in each pack.
Jim
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Jim and Janet Forbes jfo...@primenet.com
Sierra Vista, AZ URL= http://www.primenet.com/~jforbes
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Gene Slater
Chris Jon Bergquist wrote:
>
> My son has a 69 Chevelle and he wants to swap out the 307 small block
> for a 454 big block. It has a Turbo 350 transmission. What do we need
> for front motor mounts and will the 454 bolt up to the Turbo 350?
> Thanks for your help.
>
> Chris
Sir, I can appreciate your son's wanting to do the swap, but there is
alot more to this than just mounts, simple factory items, and fitting
the tranny, which it will, the tranny wont live though withouta really
good performance rebuild... ;the front suspension wont take the added
weight without replacing the springs and shocks, the brakes should be
disc also... maybe rebuild everything while its apart...safety first
afterall..... the rear differential probable wont take the added power
either...that 307 was rather anemic and the car didnot come with any
performance upgrades, i suspect.....All of the above can be done, but
for overall driveability and safety, as well as learning, do the whole
thing as a project intelligently.....go to the local library and check
various hot rod mags. and performance parts dealers and get information.
go to the drags and spend some time with the usually friendly guys in
the pits racing their cars, an infinate source of information.......
Have fun and good luck.....GENE
Joe Wiles
I don't deny some of your suggestions, but the 69 chevelle came with a
big-block and no disc brakes and the stock 8.5 inch 10 bolt will live a very
long time behind a 454. Especially a stock one. This person seems to be doing
this because he has a 454 to put in, not because he infinite amounts of money
to do unnecessary mods. Just my .02
WILDMAN
GOLDEN MIKE A
: > My son has a 69 Chevelle and he wants to swap out the 307 small block
: > for a 454 big block. It has a Turbo 350 transmission. What do we need
: > for front motor mounts and will the 454 bolt up to the Turbo 350?
: Sir, I can appreciate your son's wanting to do the swap, but there is
: the tranny, which it will, the tranny wont live though withouta really
: good performance rebuild... ;the front suspension wont take the added
: weight without replacing the springs and shocks, the brakes should be
: disc also... maybe rebuild everything while its apart...safety first
: afterall..... the rear differential probable wont take the added power
: either...that 307 was rather anemic and the car didnot come with any
: performance upgrades
Some people don't have the money do do everything at once. In answer to
your question, yes the block will bolt to the tranny. Even the motor
mounts are the same. The onl;y thing that you should need to replace
would be the exhaust. Yes, eventually the tranny will fail due to the
power of the engine, but it should work for a while. The rear end should
be okay, since even the "weak" 10 bolts are pretty strong, and as long as
you don't abuse it too much, you should be fine. The front suspension
will work with the small block springs, and actually for drag racing will
be better than the big-block springs, due to the added amount of weight
transfer. I wouldn't worry too much about the brakes either, since
big-blocks were originally in drum brake cars. It's something that you
might want to think about at some point in the future.
Bottom line: It can be done, and pretty easily. Everything should
last indefinately, as long as it's not abused. If you are going to race
it, then most of the above items will probably need to be upgraded, but
it isn't something that needs to be done right now, if you don't have the
cash to do it. Good luck, and let us know how it turns out.
Mike Golden
'81 Buick Regal, Chevy 355, TH400, 9" Ford, Paxton S/C, Holley 750DP
Don Kuhlman
GOLDEN MIKE wrote:
> SNIP
>
> Some people don't have the money do do everything at once. In answer to
> your question, yes the block will bolt to the tranny. Even the motor
> mounts are the same. The onl;y thing that you should need to replace
> would be the exhaust. Yes, eventually the tranny will fail due to the
> power of the engine, but it should work for a while. The rear end should
> be okay, since even the "weak" 10 bolts are pretty strong, and as long as
> you don't abuse it too much, you should be fine. The front suspension
> will work with the small block springs, and actually for drag racing will
> be better than the big-block springs, due to the added amount of weight
> transfer. I wouldn't worry too much about the brakes either, since
> big-blocks were originally in drum brake cars. It's something that you
> might want to think about at some point in the future.
> Bottom line: It can be done, and pretty easily. Everything should
> last indefinately, as long as it's not abused. If you are going to race
> it, then most of the above items will probably need to be upgraded, but
> it isn't something that needs to be done right now, if you don't have the
> cash to do it. Good luck, and let us know how it turns out.
>
> Mike Golden
> '81 Buick Regal, Chevy 355, TH400, 9" Ford, Paxton S/C, Holley 750DP
My opinion is the above is excellent advice, and as Mike says, most of the
parts will hold up OK as long as you don't abuse them. I'd add one thing
and that is the cooling system is probably going to be the weakest link
to begin with. Especially if the car has a non-a/c radiator. Do yourselves
a favor and mount some direct reading temperature and oil pressure gages.
They don't have to be permanent if you don't want and you can get a good
pair from outfits like Summit for around $45. These will tell you a lot
about what's going on in the engine compartment and allow you to keep an
eye on things as you're sorting things out.
My $.02, Don
Jim (cheater8) Stoltz
> GOLDEN MIKE wrote:
> SNIP
> Some people don't have the money do do everything at once. In answer to
> your question, yes the block will bolt to the tranny. Even the motor
> mounts are the same. The onl;y thing that you should need to replace
<<snip>>
Even the motor mounts are the same?
Can someone tell me then why someone, upon tearing out the big block
(402) to put in a 350, welded in new mounts in my Monte? I can't
tell for sure what was there originally, but someone welded the
loops in for the mounts to the cradle, they're not original. So,
if they work for a 350, then the 402 should be able to use them
too?
Just curious, don't have a BB yet.
Jim
Grepr
You'll need the big block frame mounts, radiator and front coil springs.
Trans should be ok.
ralph derickson
Don Kuhlman <dc...@erols.com> wrote:
>
> GOLDEN MIKE wrote:
> > SNIP
> >
> > Some people don't have the money do do everything at once. In answer to
> > your question, yes the block will bolt to the tranny. Even the motor
> > mounts are the same. The onl;y thing that you should need to replace
>
> >
> > Mike Golden
> > '81 Buick Regal, Chevy 355, TH400, 9" Ford, Paxton S/C, Holley 750DP
>
> My opinion is the above is excellent advice, and as Mike says, most of the
> parts will hold up OK as long as you don't abuse them. I'd add one thing
> and that is the cooling system is probably going to be the weakest link
> to begin with. Especially if the car has a non-a/c radiator. Do yourselves
> a favor and mount some direct reading temperature and oil pressure gages.
> They don't have to be permanent if you don't want and you can get a good
> pair from outfits like Summit for around $45. These will tell you a lot
> about what's going on in the engine compartment and allow you to keep an
> eye on things as you're sorting things out.
>
> My $.02, Don
Agree with everything -- including radiator suggestion. May have
to have old one recored to take the big block or pick up a
used one from a big block junker at the local "yard." But sometimes
with good shroud and clutch or flex fan, the small block
radiator works. Hook up a real temp gauge and try it before
getting a new one.
Kentucky Ralph
Joe Wiles
"Jim (cheater8) Stoltz" <jst...@worldnet.att.net> wrote:
>> GOLDEN MIKE wrote:
>> SNIP
>
>> Some people don't have the money do do everything at once. In answer to
>> your question, yes the block will bolt to the tranny. Even the motor
>> mounts are the same. The onl;y thing that you should need to replace
>
>Even the motor mounts are the same?
>Can someone tell me then why someone, upon tearing out the big block
>(402) to put in a 350, welded in new mounts in my Monte? I can't
>tell for sure what was there originally, but someone welded the
>loops in for the mounts to the cradle, they're not original. So,
>if they work for a 350, then the 402 should be able to use them
>too?
>
>Just curious, don't have a BB yet.
>
>Jim
Sounds like someone wanted to put solid mounts in instead of the original
rubber ones. I assure you though, the mounting location on a big block is the
same as a small block relative to the transmission.
WILDMAN
Bill LeVeaux
Be sure and get a 454 flywheel/flexplate as it is externally balanced.
Eric Neria
> And put in a new, heavy duty TH350 or a stock good used or rebuilt TH400.
The
> 454 will smoke a used 307 spec th350 in no time. The 350 engine equipped
> cars had more clutches in the tranny-the 307 equipped trannys were the
same as
> the 6 cyl trannys, with one fewer clutch in each pack.
Are they the same cases. Rather can you rebuild them with an increase in
clutch plates?
J. Forbes
In article <53loa9$t...@sahara.enmu.edu> ner...@hazelnut.enmu.edu (Eric Neria) writes:
>From: ner...@hazelnut.enmu.edu (Eric Neria)
>Subject: Re: 69 Chevelle 307/454 swap
Yes, the only real difference is the number of plates in the clutch packs.
You can get the heavy duty type clutch pistons, or have the light duty ones
turned down, to fit the extra plates in.
BTW, over the years, most of the TH350s have ben rebuilt a time or two, and
often tranny shops automatically swap in the better parts-mainly so the tranny
will last thru their warranty period. Also, with the TH350, most shops dont
rebuild the tranny that was in that particular car, but put in a rebuilt from
their stock.