small block vs big block

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aprfct0

aprfct0

1969 Notch
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I have a 1969 barracuda and was wondering if there were any suspension differences from factory between the small blocks and the big blocks. Thanks for any help.
 
big blocks had thicker torsion bars .....but they are not required ...you can run a big block on slanty bars ....just preference on how stiff you want the front end
 
Thanks rani do you know what size the small block and big block t bars are?
 
not right off i think someone will chime in with that info

if you put thicker bars you might want to weld in gussets ..i have seen ppl put in way thicker bars and actually break the torsion bar mount and make the car into a pavement plow
 
LOL that would not be good. Thanks for the heads up. I have heard that the slanties we different bars, but car is factory 318 and with the factory ride height the front was way stiff. But my plans for the car might have changed since I have a friend with a fresh machined 440 I can get.
 
aprfct0 said:
LOL that would not be good. Thanks for the heads up. I have heard that the slanties we different bars, but car is factory 318 and with the factory ride height the front was way stiff. But my plans for the car might have changed since I have a friend with a fresh machined 440 I can get.
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i have had better luck with big blocks on slanty bars for some reason on a street car ....i have a 72 swinger special with a 440 on slanty bars now and its a better ride than when i had the 318 bars the car came with.....

i think the diameter varies to suspension packages on different car regardless engine size.....some had HD suspension and so on.

i think its a trial and error untill you find what rides best for you...i have heard that the thicker bars make for a rougher ride.
 
It would make sense that the thicker bars are rougher. Just seeing what can take the weight even though its only a couple hundred pounds more.
 
The MP catolog or there chassis/suspension book has the diameters listed for stock and there own upgrades bars. The smaller the engine, the smaller the T-bar is. The smaller the T-bar, the ride will be bouncing more.
Rear springs should be upgraded as well.

The T-bar mount or anchor in the frame is welded in right the way the factory did it. What Rani mentions is when the inside becomes rusty a s wears away the inside. You do not notice from the outside. Ripping the floor up is not exactly what I would do in order to make myself feel OK.
 
i would do sub frame conectors too ....regardless of engine size

i have a slant six car thats getting them ......they improve sooooo much and make the car feel more solid
 
440Ken said:
K frame and exhaust manifolds can be a headache
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true ....i have done a few BB swaps and a SB is more plug and play

a SB can use headers which is big plus and it all drops right in and parts are cheaper and easier to find

A BB requires mods and headers dont work unless you use big $$$ headers.
K-frames have options but any option requires work.

i have done DC k frame conversions ....thats a lot of cutting, measuring , welding ....the end product is very nice and functional though

schumacher mounts are another option ....a lazy option ...those are poor. then you need a torque strap to compensate for poor mounts ....the good thing about those is that they are always available and usually not too expensive.

or there are factory BB parts ...which are rare and huge $$$

a BB is nose heavy and arguably a SB is faster but lacks the WOW appeal of a BB.

i raced a 340 and it was faster than the same car with a 440 .....but a 440 has more bragging rights on the street.

Small blocks have much better handling with smaller effort., are not as sexy as a BB
 
you really should decide what direction you want to go with your car. for strictly drag racing duties the smallest diameter slant six bars are ideal because they allow the best weight transfer. if you want to have a daily driver that handles nicely, i would suggest at least a .92 T-bar. for spirited driving you'll need a 1.00" bar or bigger.
remember that most A bodies are under 3200 pounds, that's pretty light.
my OP? nothings sweeter than a high strung small block.
yep- pauly
 
,Slanty 6 bars are used a lot in drag racing. I am building a road race / street 67 notch, planning on 1.03 pst bars. I rewelded the rear torsion bar receptacles in the transmission crossmember. The factory welds are pretty rough. mine was also a replacement crossmember, i removed the old rusty and messed up floor, and welded in a new floor, the.old crossmember ws ganked up by a previous owner, so i replaced that as well with one from my donor car. It was a really clean relatively rust free crossmember, i did reweld the mounts, and brush reprimer it on the inside with thick coats of epoxy primer after getting it sand blasted on the inside.

I would size the bar to the engine combination you want to run. I believe.slant sixes with A/C use 318 v8 bars but im not too sure on that. I used to do big block B body stuff only. Then life got in the way. Wife, kids, house, job, etc 20 years go byand my beloved B bodys are now made of unobtanium. This is why i got my 67 notch. Still somewhat affordable. But since its smaller in the engine bay, im going to build a hot high revving 318, 4 speed trans, and 8.75 rear. I want a well balanced car thats fun to drive and can accelerate, brake and handle like my 07 mustang GT. And i am looking at bang for the buck. Small blocks fit better and are relatively cheap to hop up these days compared to B/RB iron.

Check out article pinned to engine quests website about their all new magnum head castings that phr magazind used on an old school 318 rebuild. 402 hp at 6,200 rpm and i think 375 foot pounds of torque. 9.8 to 1 compression. So its pump gas friendly. Your notch is only 2,800 pounds with a smallblock. A 400 hp small block should move it rather well

Build what suits your tastes. But id go with a hopped up small block. If its already in your car use whatcha got, save yourself some headaches. You know it fits, hop it up

Its all in what you are using the car for.

Matt
 
Rani;

The big block can be brought down to SB weight through aluminum everything. So, handling can be as good as a small block. It's only nose heavy when dead stock
Or not with a lot of iron replacement parts.

The swap mounts are fine. I have them in use before and now. They can break if you do not take care when removing the engine. I have not yet broken them in car while in use.
The torque strap has also been employed since the poly lock mounts were not available at the time. If they were, the strap is really not needed.
Serious power applications in the past would use ethier a chain, turnbuckle or a motor plate. The turnbuckle is really no different than the torque arm Schmaucher offers. It's just his is nicer and installs really nice.

Ultimate speed is easy to do with bigger cubes. Your 340 can be quick, but I could never ever say it'll conquer a 440.
 
Torsion bars:
318 - .85
340 - .87
BB - .89

Big blocks also got a larger sway bar than small block cars. Otherwise there wasn't a difference. IF you think 318 bars are too stiff then you've driven too many GM cars (just my opinion - not trying to be an a$$). I've driven my son's 383/4sp Barracuda with 1.14" bars AND KYB shocks. I didn't think it was too stiff... I'd rather have .990" bars for my 67 convertible, but I got a good price on a pair of .890" bars so they will go in with a stock big block sway bar.
 
I will be using the car as a cruiser, probably will never see the track. Not really worried about having excellent handling. I have never driven a GM car by the way (besides my work van). I have had a 84 cj7 with a four inch lift, leafs all the way around. That thing was stiff. Then I had a 1997 Ram 1500. And now you see what I have now. How the car sits right now it is not too stiff but I dropped the front close to 3 inches from where it was when I bought it. And thanks again for all the info. It seems if I buy the 440 I will be going somewhere close to the .90 bars.
 
GM cars are mushy with their coilovers and x frames and all that jazz......never understood that.


torsion bars are better set up
 
I must say the little bit I have worked on these torsion bars system the better I like them. Like I said I had all trucks so I am in a completely different world than what I am used to. Hopefully I can keep reading up on all this good information on FABO and learn a thing or two.
 
RaniDart70 said:
GM cars are mushy with their coilovers and x frames and all that jazz......never understood that.


torsion bars are better set up
Click to expand...

Wow X Frames. Yes GM did do that from 1958 to 1964. I had one a 1960 el camino. This was based on a fullsized impala , belair , biscayne body. Had the jetage styling. Very weak design.

Yep torsion bars r the way to go. Chry co did that along with the leaning tower of power to help create a lower hoodline.

Still liked the look of my 60 elky tho. But like my 67 notchback better.
 
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