I know a million people have put 455's into their A-Bodies. What are the common problems associated with the swap? Manifold clearances? Engine mount placement? Linkage placement? Tranny dipstick placement? Suspension issues? I'd like to hear about the problems people have had with this swap and how to avoid them. Thanks, Grayson
This seems like a pretty good link to all the steps required (and parts) to do the swap: http://www.atlantabuick.com/EngineSwap.htm Todd
I would like to stick with my TH350, it shifts way to nice to get rid of. The link above is for 68 - 72. Anything different for '67?
The link provided above is more for the '68's and up. The '67 is one of a kind year and there are a lot of differences when it comes to swapping to a big block. For example, the frame pads are different then the '68's and up. I put a '70 455 into my '67 Special and can tell you what you need to know for the '67's. You need to install the engine mounting pads and motor mounts from a '67 GS400. They are a one year item only, so good luck! I used my existing fan shroud with no problems. Clearance for manifolds is just fine, just tighter. The tranny dipstick placement going from my SP300 to the TH400 fit just fine. The tranny kickdown switch is the same for the SP300 to TH400. I can't remember right off hand if the linkage is the same. I think it is, at least maybe just the last part of it is different. I'll look at it tonight and get back to you. I would highly recommend using a TH400 tranny because the TH350 is rated for max of 450 ft-lbs of torque. The 455 puts out 510ft-lbs of torque. Get the correct Tranny mount, and you'll have to move the tranny cross-member back a few inches, (your frame already has the holes drilled for the TH400). You'll need the driveshaft from the big block car (its thicker, bigger yoke and shorter). The hook for the emergency brake cable that attaches to the tranny crossmember is shorter. Get that one from a big block '67 too. You'll have to have your exhaust system redone. I would recommend 2 1/2" dual exhaust all the way back to bumper with an X pipe. The small block fuel line is a smaller diameter line, so I installed the big block fuel line into my Special and used the Special's existing fuel line as the return line. You will have to get the sender unit for the big block, it has the extra tube for the return line. If you can get the brake shoes and brake drums from the GS400 I would do it. I put the disc brakes from a '78 Fire Bird into my car LOVE IT! but that's a whole 'nother ordeal. You'll need the bigger radiator from the GS400, its has more rows. I used a four core radiator. The stock one for the 300ci is too small and you'll have over-heating problems. I left my stock suspension in when I originally did my swap and had no problems. In fact it road just a little lower and I liked the look. The Special weighed only 3200- 3400lbs, and the 455 really made it scoot. I hope I got everything. If I forgot something let me know anyone:beer If you have anymore questions about doing this swap feel free to email me or post them here. I'll answer them as soon as I can.:TU:
If you keep the turbo 350, better make sure it has been built to handle the 455's torque! Otherwise you may blow it to pieces! BOOM! Brian :eek2:
I see TA has the motor mounts and frame pads...they want a fortune. Nothing else is interchangeable huh?
I don't think so. However, you can buy the motor mounts from about anywhere, they are standard GS 455 mounts. I bought mine from Carquest. The frame pads are available from several places, T/A, Poston, etc. But they are right about the same price no matter where you buy it from. I got mine from Poston, T/A's are just as good. Brian
I started aquiring the parts for putting a 455 in my '67. My needs have changed, I have frame pads, oil pan and a 4 row radiator. Make me an offer on these parts and drive on over to scoop them up.
The frame pads AND motor mounts are one of a kind for '67. The '68 and up 455 motor mounts are not the same as the '67. The options I've been able to come up with is to either buy some motor mounts from someone here on this site, scour the junkyards hoping to find a '67 GS400 with its motor mounts intact, buy the frame pads and motor mounts from TA performance that would let you use the later '68 and up 455 motor mounts which are still widely available from any auto part store. I have a set of these mounts but I'm going to send them to kantor to have them revolcanized - which is cheaper then buying the pad/mount kit from TA. If you go to a auto parts store and ask them for a motor mount for a '67 you will get the '68 ones and they may have the right hole but will have the wrong angle. Don't use them. Hope this helps, welcome to the '67's :TU:
I will soon be pulling a 400 out of a 67 lark. It has a 350 behind it. I don't know if they are correct or not... the car was kind of pieced together. WHen I get them out, I will take a digital picture and maybe someone can identify if they are right or not. Anyone know what these typically sell for?
One more thing I forgot to add, The TA performance frame pads and motor mounts will raise the engine block about 1" on the '67's, in this case you most likely have clearance problems with your fan and fan shroud. Thats the main reason I'm sticking with the stock '67's motor mounts. On the other hand the 1" extra height will give you more header clearance.... *decisions decisions....* Steve, if you can find the Block ID on the 400 we can tell you what year it is.
engine swap My 400 from my 67 gs is at the machine shop right now for a rebuil. I am guessing they may call and tell me that it is not rebuilable, just guessing. If that happens, I will no longer have a numbers-matching 67 gs 40, my dream car (except this one, unlike the one I bought new, has no A/C). In that case, I have been thinking big, maybe 455? How much trouble is it to replace the 400 with a 455, and what do I gain. This is a driver/cruiser that I already have way to much money in, but, life goes on. A pm would be nice. Thanks, Lloyd
