Don Terrill’s Speed-Talk

Hello,

I am looking for stamped steel (stock appearing) 1.6 ratio rocker arms for a Pontiac 350 engine. (or 400, all the same).

Can be stock or aftermarket.

Will any particular 'other' brand work? BBC?

250 l6 CHEVY.. They are 1.7 and 3/8" stud. If stud diameter is optional then use BBC rockers. There is a bit of rocker stud alignment to over come but no big deal.
There is also after market"stock appearing rockers" on the market and some with roller tips if alowed but spring pressures on a pontiac can be changed easy if stock diameter springs are required

the factory made 1.65s,believe they are avail aftermarket.Make sure you clearance the pushrod holes,you might have a bind in that area.Tom

ProPower engines wrote:250 l6 CHEVY.. They are 1.7 and 3/8" stud. If stud diameter is optional then use BBC rockers. There is a bit of rocker stud alignment to over come but no big deal.
There is also after market"stock appearing rockers" on the market and some with roller tips if alowed but spring pressures on a pontiac can be changed easy if stock diameter springs are required

I have not been able to find any after market "stock appearing rockers" for Pontiac in 1.6 ratio.
If you know a source I would be very grateful.

racerx1622 wrote:

ProPower engines wrote:250 l6 CHEVY.. They are 1.7 and 3/8" stud. If stud diameter is optional then use BBC rockers. There is a bit of rocker stud alignment to over come but no big deal.
There is also after market"stock appearing rockers" on the market and some with roller tips if alowed but spring pressures on a pontiac can be changed easy if stock diameter springs are required

I have not been able to find any after market "stock appearing rockers" for Pontiac in 1.6 ratio.
If you know a source I would be very grateful.

Years ago I used to buy Elgin 1.6 ratio stamped steel Pontiac rockers. I don't use them anymore so I can't provide a part number at this time.

I used to use PAW, but not sure if they're still around?

I don't think the BBC rockers will work.
(use the rocker studs though )

Melling makes--or used to make--stock replacement 1.65 ratio rockers for Pontiac.

The price was insanely high. More costly than Comp Magnum roller-tips. I don't see them in the current catalog, though.

The pushrod holes WILL have to be opened up or the pushrods will bind.

Later Edit: Bare 1.65 Melling rocker arm = MR848

Rocker arm MR848 is included in a kit with the pivot ball and nut as Melling P/N MRK 532.
$15 EACH.
http://www.summitracing.com/parts/MEL-MRK-532/

UPDATE

I had casting #46 heads, and installing the 1.65 rockers gave us a little more torque off the corner (IMO)
Exhaust keeping 1.5.
But we just changed to casting #18 (shaved .015) for more compression (about 10.0 I figure, from 9.2) and it seems we lost power.
???

One thing, I did not increase jet size, and that might be it. But i'm curious about the lift.
Anyone recommend moving 1.65 from intake to exhaust?

FYI
Pontiac 350, stock +.040, 2bbl intake and carb., stock exhaust dual 2" with x pipe.

Why not use 1.65 on both?

Also, are you using high enough octane gas for the cr now?

did you check for pushrod clearance with the new heads? you could be binding.

Ok, just pulled the plugs (and they all look slightly oily)
I also drained the oil pan, and after one race I lost 2 qts.

I did a compression check, and they are all 165-170.

I'm not binding anywhere.

The cam is Comp XE262H
110 LS Intake 262 (218 @.050) .462 lift
Exhaust 270 (224 @.050) .470 lift
Intake centerline 106

I'm wondering if the new heads are leaking bad past the valves...