I am planning on putting a 327 sbc into my 92 pontiac firebird. it originally came with a 3.1l v6. I have had three different people tell me it wont bolt up. But no one has said why. I believe I have a 700r4 transmission. What is the problem?

 

You need a v8 trans for it to bolt up. Also, see what heads are on it, if its got its original heads, it may not have accesory holes. A 350 would be better.

 

what about just an adapter? is it just the bolt pattern? and what do accessory holes in the heads have to do with it?

 

or how about a new bellhousing? i really want to make this work without spending too much money. i am getting discouraged now, i already bought the engine.

 

nevermind the bellhousings are cast with the trans... but there must be an adapter somewhere

 

i'll tell you that the accessory holes are needed for the alternator and AC.. as for the trans stuff, good luck.. i have no idea.. i'm a v-8 stick guy..

ok just did 1 minute of searching on google and found that the 700r4 will NOT bolt to a v-8.. the v-6's are 60degree while the v-8 is 90degree.. bolt patterns are different.. you will have to get a v-8 trans..

what is your budget for the swap?? i hope more than $2000

 

if your car came with a v6 in it and you want a v8...you need:

front v8 springs
a v8 700r4 ( i have heard of people custom fabbing their v6 700r4s up to a v8 but y would u?, they are weak and it would be more expensive than getting a v8 one)
a v8 k member and motor mounts. (which can be done by swapping your k member with that of a v8 car's or an easier thing to do would be to remove your v6 motor mounts and just weld on v8 ones)

 

yeah the heads have accessory holes, my budget is not more than 2000, and i think i am going to try the custom fab thing, are the bellhousings the same dimensions and just different bolt patterns? and as per the sticky at the top, i do not believe i need a new k member i should be able to bolt new mounts in the v8 location. right?

 

Right, just put the V8 mounts in the V8 holes of the crossmember.

The V8 and V6 bellhousings are completely different.

 

Not a great bit of advice. You cannot make the auto work, it isnt gonna. You dont need to change the k member, just the mounts. The mounts dont need to be welded, either. The holes are already in the k member, its the same part, drilled for both v6 and v8. BTW, the brake lines will be running where you need to put the v8 mounts, just shift them over and put them in the next set of holes.

 

y would u do the custom fab thing?

just get a v8 tranny and weld on some v8 motor mounts
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not a great bit of advice? what do u mean?
i told him to get a V8 Tranny and install V8 motor mounts!? WTF?

 

ok i ive accepted the fact that my trans wont work with the 327. now lets say i could find a th350 for cheaper than a v8 700r4. How much extra work is it to make that fit? would i just be better off spending a little extra money for the direct fit?

 

th350 dont belong in thirdgens my friend... but they can be installed.

 

Its bad advice because you told the guy he needs a V8 K member which is completely false, and you told him to weld the mounts in for some god awful reason. The K members are exactly the same, and drilled for both sets of mounts, you just unbolt the V6 mounts, and bolt the V8 ones in their appropriate location.

 

I would just like to say thanks to everyone for their help, i found a great deal on a v8 700r4 i appreciate all the advice, and soon i should be selling a good running 3.1 v6 and newly rebuilt (and matching) 700r4 combo if anyone is interested ill be sure to mention it to the guys in the v6 section too

 

yes i did say that, and i have heard of people doing that....but then i corrected myself in saying that all you have to do is install v8 motor mounts and get a v8 tranny.

so my bad advice was corrected into good advice. at least im not trying to convince him that a v6 tranny will mount to a v6...cuz it wont....

 

Of course it will!

Unless, of course, you meant to say a V6 tranny will mount to a V8...cuz it won't...

 

 

2.8 did not come with a 700r4 it came with a 200r4 like the s10's.unless firebird motors are diff?

 

haha yeah thats what i meant! srry i was a lil tired!

 

That is incorrect. 2.8's either had the TH200C (3-speed auto with lock-up torque converter, '82-'83), or the TH700R-4.

Only the TTA had the TH200-4R.