I know the 85s are the better of the 307, but how would that compare to a set of headers. Anyone have real numbers?

This is a stcok 350 in an 84 Cutlass.

Thanks.

sb

 

Manifolds are no comparison to headers. Olds manifolds are rather restrictive from the get go.

 

Ok.

I have built LOTS of mopars. I've even built a few fords. I've had the opportunity to drive them back to back with manifolds and with headers. To be honest, every time I did the swap to headers, I felt like I spent a lot of $$$ and time (especially on the mopars they suck for putting in headers!!!!) for very little return. In fact, the last 5 Mopars I built I used the cast iron manifolds. These included 3 slant sixes, a 318 and a high compression 400.

If this in not the case with Oldsmobiles, I'll spend the $80 extra (and time?) to put headers on over the cost of the JY cast iron manifolds.

Talk me into it.

sb

 

What other modifications have you done to the engine? If you don't have an aftermarket intake manfiold, high quality SBO heads, an aftermarket cam, and good carburetor then headers would be a waste of money IMHO. Of course, if you want to do all of these mods to your SBO then headers are a good place to start. You will gain decent HP and have a difference in the exhaust tone.

 

Good point Olds 64.

All those mopars listed in the earlier post had more into them than this 350 does...the slants all had oversize valves, significant porting, milled for high compression, Erson 270* cams and at least a stock 2bbl or holley 350, 2200 stall converter backed by a 3.55-4.10 gear. The 318 had oversize valves, bored .060 over, 214* @ .50 cam, high compression pistons, 625 cfm 4bbl, AM intake (single plane), 2500 stall convertor backed by a 3.55 gear. The 400 was milled .100 for compression, AM 4bbl intake (dual plane), mild after market cam (don't remember specs), backed by 3.21 gear.

The only aftermarket (high performance) parts on this olds build are: "high performance" distributor, 2500 stall converter, FANCY summit transmission (WAAAY more transmission than needed), and as soon as I get the exhaust put on, 3.42 gears in the rear end.

Otherwise it is completely stock short block with 5a heads, factory 4bbl intake, and stock replacement parts. Will I one day build a bigger & better motor? Maybe. The 403 I was looking at is GONE. So, for now, I will keep my rescued 350.

sb

 

Headers on a 140 horsepower motor is definitely not worth the aggravation.
5a heads came on 307 motors, not 350's.

 

Sorry. 3a heads....wait...a stock 350 Olds makes 140HP?

Wow.

sb

 

No. I think the lowest rating was either 175 or 180 HP. 140 was the 307.

 

Either way, it's still sad lol.
You don't even start having fun until about 300 horse.

 

Well. I need to get this one moving under its own power and find a motor to build on the side. We'll see.

sb

 

Any ideas if these will fit my G-body cutlass?

https://classicoldsmobile.com/forums...ds-shield.html

Thanks.

sb

 

The exhaust wouldn't bolt up because the outlet on the passenger side manifold has the wrong angle on it.
If you are having a custom exhaust made they can be made to work.

 

Cool.

sb