Hey Folks,

After a couple years, I finally bit the bullet and bought a 455 to swap the original 350 in my 68 S convertible. I also bought a 3.23 posi out of a 69 Gran Prix to go with it. The car has a newly rebuilt TH350 with a 2200 stall I think; higher than stock anyway. I am aware that a BBO has the potential to kill this trans/rear end combo. I will only be using for cruising around town and heading up to the cottage. Lots of smooth highway driving. My concern is the cam may be a bit radical for my intended use. I spoke to a local Olds mechanic about it, and he thinks I should just try it out first. I will be putting a regular Performer (no air gap) intake and quadrajet carb. I like the original look. Any opinions on the build or cam would be appreciated.



Motor Specs



Motor was rebuilt about 10 years ago.

Previous owner gave specs, and I verified all I could see:

.60 over F block 455

J heads ported with larger valves installed (look very nicely done)

TRW pistons- says about 9.75 CR with stock gaskets

Harland Sharp roller rockers 1.6 - 7/16 studs for heads

High tension valve springs

Pushrods, lifters

Dick miller custom cam specs-

Dur@50 Dur@006 Gross/Lift Lobe/Sep

236/246 280/289 .552/.552 112/108

Alum valley tray

Double roller chain and gears

Rings, bearings,HV oil pump, etc.



It originally had a Demon carb on top of a Performer Air Gap, but that wasn’t part of the deal.

He thought it made about 450 to 500 hp. He said it went like stank.



Thanks,

Ron

 

That engine, intake combination will be about 2" taller than a 350 with Quadrajet. You can judge if there will be hood clearance problems. I'm not saying there will be, just giving you a means to figure it out.

The cam is indeed radical. And also judge whether you will still be driving smoothly as Mustangs for 8 miles around come sniffing to try to taunt you into racing because of the shake and exhaust sound.

Cool engine, but your intent may be better served with a milder cam. You can retain most of the power with a quieter idle if you choose a milder roller-cam. You can still make that change with the engine installed if you try the cam but don't like it.

 

Thanks for the input Gary. (love the Vista!)The motor was installed in a 68, so it will fit just fine according to PO. Funny comment about the taunting by Mustang owners! I'm too old to get pulled into a macho run, but you never know... What cam would you suggest for my build?

 

Cam is a little big. But if the springs on the heads aren’t already for a roller then you’ll need to change them if you go that route.
If it’s a flat tappet then I’d the Erson Hi flow 1, 228/228@.050 with .500 lift on both. Should give you some tone but still drive well, IF the carb is tuned correctly.

 

Thanks cutlassefi, I would like to make the most of what I have. I am not stuck on any carb yet with this setup, so I am open to any suggestions regarding this as well (including EFI). Waiting on my engine gasket kit to come in so I can finish cleaning it up. Looks like a frost plug has build up around it, so those are being replaced as well. Can I make the most of the current cam? What would be the best way to take advantage of the current setup?

 

I was thinking something similar in duration to what culassefi recommended.

I'd consider a roller cam with around 225/230°@0.050", 110° LSA, and lift 0.500" or a bit more. That's something you could buy from Comp, if they have it in stock.

As Mark pointed out, changing to a roller requires specific springs, so its not as simple to change as his recommendation would be. The advantage of rollers is that they give a bit more power versus a flat-tappet cam without sacrificing drivability.