Im Pissed Off!

[combustion]

ok, her is the deal. i have a 1970 c10 tha originally had a 307ci in it. since the motor was tired and had no compression on 2 cylinders i decided to go bigblock. i purchased a 1994 454ci that came out of an 2500 p/u. it was tbi so i purchased an eddie mani and carb and bought an electric fuel pump because the block was fuel enjected. so i put the engine together and find out that the flywheel is to large for the tranny to fit. so i swapped it out with the small block flywheel (its a TH350). as i was droppin the motor in with small block mounts like the guy at performance checkers told me, i notice that the tranny needs to be moved at least 6 inches or more back for the mounts to be able to bolt up the chassis. im pissed because the guy at checkers told me that it was gonna bolt right it and it looks like its not. so what do i do? is there any custom mounts to use? tranny mods? here is a pic so u can understand better

[lamar]

No idea, but I'm sure somebody will jump in and help you out. Good luck!!!

[kwmech]

Well first off, you cannot use a small block flywheel on a 454 bcuz of the balancing. The 454 is externally balanced and the small block internally (sans 400sb). Second what you will need is the big block frame stands, which set the engine back 1'' from the small block position. Not quite sure about the 6'' deal you are talking about.

[rage'nrat638]

there are
6 cyl engine towers
sbc engine towers
bbc engine towers
for these trucks..
i also think they used a high hump floor pan on the big block trucks if memory serves

there are also different radiator shrouds needed for different engine combos.

the automatic trans cross members has to be moved with these different engine combos..

thus the different drive shafts needed..

the guy at checkers a
check the FAQ section all of these mods have been done many times here.
hope this helps..your pal mark

[krue]

Just move the tranny crossmember back to where it needs to be (assuming it's an auto tranny). They just bolt in and the frame is straight for days under the cab.

[combustion]

Originally Posted by kwmech

Well first off, you cannot use a small block flywheel on a 454 bcuz of the balancing. The 454 is externally balanced and the small block internally (sans 400sb). Second what you will need is the big block frame stands, which set the engine back 1'' from the small block position. Not quite sure about the 6'' deal you are talking about.

then what flywheel am i gonna use? the 454 one is too big and it wont let me fit the starter in place, nor fit the torque converter bolts

[combustion]

Originally Posted by krue

Just move the tranny crossmember back to where it needs to be (assuming it's an auto tranny). They just bolt in and the frame is straight for days under the cab.

do i have to redrill holes? or they are already there? yes is an auto tranny.


"They just bolt in and the frame is straight for days under the cab"""

???????

[combustion]

Originally Posted by rage'nrat638

there are
6 cyl engine towers
sbc engine towers
bbc engine towers
for these trucks..
i also think they used a high hump floor pan on the big block trucks if memory serves

there are also different radiator shrouds needed for different engine combos.

the automatic trans cross members has to be moved with these different engine combos..

thus the different drive shafts needed..

the guy at checkers a
check the FAQ section all of these mods have been done many times here.
hope this helps..your pal mark

o ok, so i need th bb towers in order to do this swap AND relocate the tranny crossmember?

[Sport/Truck]

Rule #1 don’t rely on what somebody at checker, AutoZone etc. say. Always get another opinion especially if you are going to make a big purchase.
But you found us, and there’s a ton of information here. Welcome from New Mexico!

Mark, I see you have a new avatar….can I have your old one??lol

[krue]

Just move the crossmember to where you need it and drill the holes where you need them.

[combustion]

Originally Posted by krue

Just move the crossmember to where you need it and drill the holes where you need them.

what about the drive shaft? and they guy up there said i cant use the flywheel.

[krue]

You're gonna need a different driveshaft if you're going from sbc to bbc anyways. Luckily it's cheaper to shorten one than to lengthen it. I don't see how it could be 6" out, there's not that much difference in the mounts. BTW what kind of tranny do you have that the flywheel wouldn't work? As far as I know the bellhousing patterns are all the same, so I can't picture the flywheel being the reason the tranny won't fit.

[xcracer]

get a 153 tooth flywheel for a 454, you cannot use one from a 350...period, it will prove disastrous

[combustion]

Originally Posted by krue

You're gonna need a different driveshaft if you're going from sbc to bbc anyways. Luckily it's cheaper to shorten one than to lengthen it. I don't see how it could be 6" out, there's not that much difference in the mounts. BTW what kind of tranny do you have that the flywheel wouldn't work? As far as I know the bellhousing patterns are all the same, so I can't picture the flywheel being the reason the tranny won't fit.

its a th350 like i said. the bbc flywheel is just to big for my sbc starter to go in. unless i need to get the one it came with. but the 454 flywheel is too big. the holes for the torque converter bolts are too separated.

[combustion]

Originally Posted by xcracer

get a 153 tooth flywheel for a 454, you cannot use one from a 350...period, it will prove disastrous

so do i get that one from like a chevy truck that already came with a bbc originally of the same year?

[Longhorn Man]

is the flywheel physicly too big to fit in the tranny bellhousing... ... or the converter won't bolt up to the flywheel?
I suspect it is the latter.
Big blocks always came with a TH400, the TH400 has a larget converter with a larger bolt pattern on it.
Here's a little trick i did on my caddy/TH350 deal... get a converter for a TH400, and install it in the TH350. It'll work fine.

[Longhorn Man]

wow... 2 responces while I was typing.
Get the Th400 converter, and a starter to work with the big block flywheel.

[combustion]

Originally Posted by xcracer

get a 153 tooth flywheel for a 454, you cannot use one from a 350...period, it will prove disastrous

is there a specific truck or car that came with that one? or do i have to get a custom one?

[corn]

Did you change trannys too? Ive had a 350 & a 396 in my 69 & it was a drop in deal, but I didnt change anything on the trans. Ive always gone by the rule that a big block will bolt up anywhere a small block will. Might not clear everything as far as valve covers & acc but the block bolt locations are the same...

[combustion]

Originally Posted by cornfed63

Did you change trannys too? Ive had a 350 & a 396 in my 69 & it was a drop in deal, but I didnt change anything on the trans. Ive always gone by the rule that a big block will bolt up anywhere a small block will. Might not clear everything as far as valve covers & acc but the block bolt locations are the same...

well. when i put the engine in it sits foward way too much thus not allowing the engine mounts to go in. some people in here were saying to move the tranny x member back so the motor mounts can bolt into place. im using the small block motor mounts right now on the bigblock. butlike i was asking. what car came with a 153 tooth flywheel for a bigblock? r do i have to get it custom. sorry im full of questions, but i need to get this done asap

[combustion]

bump

[1bad chevy]

454 big blocks and400 smallblocks are externally balanced so you need to use a flywheel off of one of those two engines to be correct if you dont you will mess your motor up badly when you get the flywheel get a starter for the same thing and it will work flywheels come in two sizes 153 tooth and 168 tooth and the starter can be ordered for either you just need to specify how many teeth you want they both WILL fit

[jamis]

Like others have already said you can’t use a SB flexplate on a BB without 0 balancing the engine for it. My suggestion is to call TCI at 1-888-776-9824 tell them the engine and transmission you’re using and have them recommend a flexplate (not flywheel) with the correct bolt pattern.

If they don’t make one try B&M both of the companies are top notch transmission and accessories manufactures


As far as positions go there are two sets of holes for the motor mounts one more forward then the other, are you in the most forward position? You will also need the BB engine stand and factory ones are not cheap if you can find them. This is what I would use if I where making the conversion http://www.nwautofab.com/shop/xcart/...9&cat=3&page=1

[AKChevyman]

If you go to checkers (or junk yard) and ask for a starter for the 1994 chevy then you will be able to use the flywheel that came with the engine. the starter from the 350 won't work the mounting flange is diffrent. but the tranny will bolt up to the big block. 99.9% sure all tranny bell housing's are the same for chevy's now some one will point out where I am wrong on this I hope but the flywheel and torque converter should bolt together also but you can do what longhorn suggested if they don't.

[dwaite72lnghrn]

First things first. Go to GM dealer and get a FLEXPLATE (2 sizes12 3/4";153 tooth and 14":168 tooth) for the 454 with dual bolt pattern(10 3/4" and 11 1/2" torque converter). Next get rid of the 350 motor mounts and get towers and mounts for a big block. Then get a starter for a Big Block.
As it sits in the engine compartment how close to the firewall is the engine now?
Make sure of the year the engine is when you get your FLEXPLATE as the 454 around early '90's were mark 4 and gen 5/6 and the balance is different.