I'm planning on swapping out the 300 for a 455 in my otherwise stock '67 Skylark. When it comes to suspension upgrades, what all needs to be taken care of to ensure that the car will be able to handle the new motor? Any help would be much appreciated. Thanks in advance!
I think coil springs are the only suspension parts that change to compensate for the additional weight. Maybe a beefier sway bar too?
I performed the same swap....300 for a 455. My car was very low mileage (30K), I left in the stock springs and run no front sway bar with no handling issues whatsoever, even drag racing at high speed-straight as an arrow! I would suggest new shocks depending on your goals with the car....KYB's seem to work well on street and strip. I do also have 15 X 7 Buick rallyes with BFG radials. - My 2 cents
Thanks for the responses so far. I not planning on making an 11 sec. drag car or anything, I just need something that will hold up to normal driving (and maybe an occassional trip down the track for fun).
I am in the process of the same. I am upgrading the suspension because it will be exposed and easier to work on when the engine is out as well as wanting the G-machine look and driveability. So I am upgrading to P-S-T polygraphite for the front end. I am swapping out the steering gear to a mid-late 80's monte carlo ss steering gear to get the quick ratio and modern car handling. I will be putting in a 1 1/4-3/8 front sway bar as well for handling. ONce the engine is in, I will be swapping the stock springs for EIbach lowering springs and putting KYB shocks in. But as far as what needs to be done, nothing. Many guys are using small block springs. It will lower the car in the front, but not by much. In fact, Hotchkis recommends the small block springs from their A-body line for buick 455 guys because the 455 is not nearly as heavy as the chevy(454)which is what they base most of their products on. Keep in mind though, if your springs are older, they may be more susceptible to sag than say new small block springs.
I will give my normal lecture on poly bushings. It is not a good material for suspension bushings. As far as I know NO car manufacture uses poly as a suspension bushing material. It will not hurt a lot in the front but is a disaster in the rear suspension. If you have a stock suspension in perfect condition with good shocks it will work and feel very good. Check everything, put in new MOOG bushings, new shocks, new tires and you are way ahead of when these cars were new. Add some good sway bars and you are ready to go.
I would agree with straight poly, but I have heard nothing but great reviews of polygraphite. They have lifetime warranty and will self lubricate, eliminating the squeeking that base poly will give you. If Chip Foose uses them, I am ok with going that route.:TU:
I like Foose but he is not a suspension expert. I would beat him with a club before I would let him put those oversize rims he uses on one of my cars. Opinion still stands, polygraphite is not as good as rubber for a suspension bushing. Just got through talking with Ron Frakes about suspensions and he does not like poly bushings. Ron was responsible for the suspension of the turbo regal Indy pace car, aero package on the GSX, and a bunch of other stuff. You MUST have articulation of the upper control arms in the rear supension. You loose that with poly.
I am no expert. And I am truly only speaking for the front end. Everywhere I turn, everyone uses the polygraphite from PST. Super Chevy, Hot Rod, Rod and Custom, etc.. I understand Foose is not a suspension man, but his team is well versed in it and I respect their cars they build. They use Hotchkis and PST for almost all builds. Again, I said I was going with a g-machine approach which is more inline with the Foose look. If you are looking for less stiffness and handling and more concerned with a smoother luxury feel, than rubber is the way to go.
I updated the springs to 5450, shocks and added the GS 7/8" or is it 15/16" sway bar. I am running the poly bushings and all is good. http://www.buickperformance.com/springs.htm
you want to run polly up front but not in the rear it causes binding well the rear uppers or the only ones that need to be rubber actually
I've made this swap several times and never changed anything in the suspension. Well, I take that back.....On my first swap, I put in Moroso springs in the front and hated them. I ended up putting the originals back in. As said above, I don't there's theres a ton of difference in weight between the engines.... or at least not enough to make a noticable difference.
Call these folks and talk to them about rates, etc. ESPO Springs 'n Things 75 Pine Tree Road - Danville, PA 17821 Phone: (800) 903-9019 or (570) 672-9413 Monday-Thursday 10:00 AM - 5:00 PM EST They can help you compare your stock springs with the 67 GS springs which would have been the same weight motor in your same chassis. If you want to upgrade from the small block springs (I have a 64 w/ 455 and I'd recommend it), I have a set of new 65 GS springs (non A/C car) I'd like to get rid of. $50 if interested. Email me pmg455@msn.com. Thanks Pat
