455 into a '64 Wildcat?

So I've pulled the nailhead and I think I want to swap in a BB 455/TH400 into my '64 Wildcat.
who's done it? what do I need to know about fitment issues? are there engine mount adapters or should I just fab my own frame mounts?
can I use a TH400 that comes behind a 455? what are the issues with the different trans? things that come to mind are shift linkage, crossmember and bellhousing...are any of these issues?

 

what's wrong with the Nailhead? There's a bunch of fab work to do the swap... and besides the Nailhead is a much cooler motor...

 

No replacement for displacement is my guess, and the availability of parts for slightly less. and a better Trans.

Z Man is right it would be nowhere near a drop in. and to be honest the gains you'd get would be negligible. On the other hand, I bet a few Hambers would happily take the old motor off your hands.

 

Better trans? Than the ST400 or SP400 that came in it. Hmmmm.. .they are TH400's... I guess that's one more reason down...

 

Right but the earlier BOP 400's were not as stout as the late 60's model's, at least that was the impression I got. The only caveat was teh 67 with the switch pitch converter, but even that could be replaced with conventional

 

I am not for sure but I think the length is different too, different tail shafts and mounting locations, this only matters if the new 455 is extra stout or won't bolt up. I can't remember if the mating bolt pattern changed.

 

First off the Nailhead is not BOP.... the case will take regular TH400 internals and can be beefed the same way as any other TH400..

Short tailshaft, pretty standard really.. The 455 will not bolt up to the Nailhead tranny.

 

well, I know the nailhead is way more nostalgiac and has the wow factor; I like those engines, espcially since I've been looking stuff up about them. Reason I'm considering the 455 is the nail' has to be rebuilt and I want to do some performance work. From what I've seen and have been told, the 455 is more common with aftermarket support and a little lower price.
I've also been told by some buick guys that the ST400 in my '64 was the first year and wasn't as good as the later years.

So I'm looking for a 455/TH400 combo...correct? what different styles of BOP trans should I look for or avoid? Or should I build up the 700r-4 I have in the shop instead? I have an r-4 in my '56 and I love it.

what kind of fab work are you guys talking for it to fit? if it's just engine mounts and crossmember, that's not a big deal. if I've got to open up the trans tunnel that may be more than I'd like to do on this car. it is a hard top so it's got an X-frame, don't know if all the 'cats have that or just the hardtops...
I know there'd be some adapting to do with hoses and exhaust but that doesn't seem like a big deal...

 

well, the other deciding factor on the 455 is it was that or a small block chevy. so at least I'm keeping it in the Buick family...

so far I've learned that there is a short and long tailshaft TH400 behind the 455's and I'll want to use the short shaft version. engine mounts are different so I'll have to weld plates on the frame (not the first time I've done that).
I haven't found anything on whether the exhaust manifolds will clear or what options there are for tube headers. I think I can run an exhaust pipe out either side routed the same as the single exhaust went out the passenger side.
someone also mentioned I may have to use a center sump oil pan? what different oil pans did the 455's come with?

 

You are right about the first-year '400 in 1964. its a great tranny until it goes, then no one wants to touch it. was able to patch mine up, but headaches all along the way.

If you wanna ask about the big buicks, ask these guys:
http://taperformance.com/
These guys have been doing buicks for a long time, and have tips on o/d swaps.

 

With more than 300K on my '64 TH400 in my '64 Riv. has been nothing short of relibility with normal services. I've owned this car since new & short of putting in a new front seal at 120K has propelled my heavy Riv. down the 1/4 many times, even pulling the left front on occasion. I don't know where these relibility issues come from, but as far as I'm concerned they are mostly BULL!!!!! Some parts may be harder to find than '65 up 400's but are available. Internally, the '64's, they are the same as any 400 & parts swapping can eleviate some of those parts problems. Just my dimes worth. Not reliable, not strong, hogwash!!!!

Tom Telesco

 

well I found a 455/TH400 runner. a guy nearby bought a running car, drove it around for a while and was going to swap it into a slightly older buick, then never got the project he wanted to build. so I got the engine.
found a center sump oilpan that I need to clear the odd crossmember/steering drag-link. I need to get the frame pads off of a 455 car and just weld them onto the 'cat crossmember. Not sure yet but I'll find out when I try to stuff it in the first time if the trans output shaft/housing need to be changed.

between moving and working on my other projects I have going, plus oh yeah, I have a job too, I'm hoping to get this done in time for Paso. cutting it too close for Viva, plus I'm not even entering the show there, just cruising over to spectate.