I have a service replacement intake used for 1967-69 302 CI Z28's. This manifold will be sitting atop a solid cammed 327 with 247/254 @ .05 and about 280 @ .006 (a fairly aggressive ramp), using 1.6 full roller rockers. Compression is 11.0, Crower rods, 1 5/8" headers. Carb is Quick Fuel Q750. Heads have been race ported and matched to a Fel Pro 1205 gasket.
What is your best advice for porting the intake.
Thanks in advance,
Joe

Some people may not recommend this, but I would only match the gasket to these ports. No belly smoothing roofs or floors as most intakes need that rough surface to help fuel distributions. Out of curosity, was the last 3 digits 472?

I’m not big on port matching intakes, that’s not where the power is, its in the plenum.
Sounds like you’ve got a nice little old school hi-winding 327 build going that should make decent power.
I’m assuming the is the dual plane z28 intake, if so stick a open spacer on it, if you do this you can
shape the plenum entry some. Dual planes aren’t easy to port, some runners will be 30-50cfm down
from other, you’ll need to find out which ones are weak and work those. Sharp turns in the dual plane design
will need work too. Also don’t gasket match, “port match” the intake to the head intake port as the gasket can
often be bigger than the head. Also youre trying to avoid going from small - big – small, and this is what
happens when people open up and gasket match intakes, youre going from a small port in the intake manifold
to a large gasket match and right back down to a small pushrod pinch - this will make the fuel fall out of the
air stream and cause puddling on port walls, not what you want.
Work the plenum, turns in the bad/weak runners and a mild port match to the heads.

Some people may not recommend this, but I would only match the gasket to these ports. No belly smoothing roofs or floors as most intakes need that rough surface to help fuel distributions. Out of curosity, was the last 3 digits 472?

Its a 14044836.
I wouldn't mess with an original production piece.

I’m not big on port matching intakes, that’s not where the power is, its in the plenum.
Sounds like you’ve got a nice little old school hi-winding 327 build going that should make decent power.
I’m assuming the is the dual plane z28 intake, if so stick a open spacer on it, if you do this you can
shape the plenum entry some. Dual planes aren’t easy to port, some runners will be 30-50cfm down
from other, you’ll need to find out which ones are weak and work those. Sharp turns in the dual plane design
will need work too. Also don’t gasket match, “port match” the intake to the head intake port as the gasket can
often be bigger than the head. Also youre trying to avoid going from small - big – small, and this is what
happens when people open up and gasket match intakes, youre going from a small port in the intake manifold
to a large gasket match and right back down to a small pushrod pinch - this will make the fuel fall out of the
air stream and cause puddling on port walls, not what you want.
Work the plenum, turns in the bad/weak runners and a mild port match to the heads.


I ported a pair of stock, iron 461's with 2.02/1.6. The flow numbers are very good with intake 250 @ .5, 248 @ .6; exhaust 182 @ .5, 194 @ .6 and 202 @ .7.
The "pinch" zones adjacent to the pushrods and head bolt areas were opened as much as possible.
I don't think that I'll have room enough for a spacer. I'm planning on sitting the carb directly on the manifold. What type of work do you recommend for the plenum? AFAIK, the runners associated with the upper plenum half should not flow as well as the runners associated with the lower half.