Which Cam-SBC Guru's

[Its Just Me]

My rear main seal and front trans seals are both leaking, so my plan is to pull the engine this winter & replace the seals. While the engine is out I'm considering a cam change, but only if it will make enough difference in engine performance to justify the additional expense.

 

Here's what I'm working with:

'72 Monte Carlo Custom

Air conditioned

TH350

3.31 posi rear gear

Coan 2400-2600 stall converter (not currently in the car, but will go in w/this project)

355 SBC

Estimated 8.5:1 CR

Flat top, 4 valve relief pistons (verified w/scope)

I'm considering changing head gaskets to optimize quench and maximize CR

OEM 487x iron heads (76 cc chambers)

Comp roller tip rockers 1.52: ratio

Weiand dual plane aluminum intake (similar to edelbrock performer)

Original Q-jet carb (I may send it to Cliff Ruggles for rebuild/mods)

1-5/8 headers w/2-1/4" full length dual exhaust, glass pack style mufflers

Points distributor converted to Crane electronic w/hotter coil

Currently 12d initial, 34d total, all in at 2400, vac advance limited to 8d

87 octane w/up to 10% ethanol, no ping

100% street driver (no track time) but I like my stuff to run good.

 

The current cam specs are:

Comp Cams "High Energy" Hyd flat tappet

264 advertised duration

214/214 @ .050

.469/.469 lift w/1.5 rocker ratio

110d lobe separation

This cam is currently in the engine, bought & paid for, it just doesn't seem to get after it. I don't know if it was ever degreed.

 

I'm considering:

Option #1:  Clay Smith "Street Smith" Hyd flat tappet

264 advertised duration

214/214 @ .050

.450/.450 lift w/1.5 rocker ratio

108d lobe separation

 

Option#2:  Clay Smith "Torque Smith" Hyd flat tappet

274 advertised duration

224/224 @ .050

.450/.450 lift w/1.5 rocker ratio

108d lobe separation

 

Will either option give me enough seat of the pants torque improvement to justify a cam change/expense? Which option for my combination? Or should I just keep what I already have?

 

I know a HR and some smaller chamber heads to bump compression would be the best way to go, but that is a future project. I'm just looking to make what I currently have work together better for the next few years.

Any thoughts?

 

Thanks

Scott

 

 

 

 

 

[72MC]

 

 

 

"Will either option give me enough seat of the pants torque improvement to justify a cam change/expense? Which option for my combination? Or should I just keep what I already have?"

 

NO !!!!    Keep what you have or rebuild it to what you want to accomplish.  If you want that thrust in the seat of your pants it is gonna take some cash.  You can build a SBC or BBC with big torque/HP engine but can the tranny take it?   Can the rear take it?   Going fast cost $$$$$.   Until you can pay the piper, enjoy what you have.  Just my 2 pennies. - Dave

[Sam (Bones)]

Dave hit the nail on the head!

With a 350 and only 8.5 compression and wanting to run 87 octane, leave it alone or you are just throwing your money out the window

[Its Just Me]

Dave & Sam you both confirmed what I already knew, thanks!

I think my biggest problem (if you can call it that) is that I'm a big block guy & I'm having difficulties adjusting! I haven't messed with small blocks for 30 years. 

Maybe I'll give into the force & put my 427 in... that should solve the torque issue! 

Scott

[Sam (Bones)]

if you want some torque and be able to run 87....there is a way....there's no replacement for displacement!

 

but I would lean towards a 454