How did you all get more power out your 327

[Jrivera88]

Just looking for some ideas . Car has a 327 /210 w/ a th350. Did some mods get about 268 and 220 to the wheels he had it dyno and gave me the sheet . He put a stage one cam / upgraded to 4 bbl / intake . My c10 I did a ls swap , not ready to do that to this car , and don’t really want to . Goal is to get about 300 to wheels and I’ll be happy .

[rocco376]

I have the original 327/300 in my 67 Corvette.  Had it rebuilt at LRB Performance in Franklin, NJ with the hopes of getting around 400 HP.  Bored .30 over, Hedmann headers, AED performance Holley Carb, Cam Motion hydraulic roller cam, Chevy LT1 aluminum manifold, and AFR aluminum heads.  Engine dyno'ed at 413 HP. 

[David K]

Replace the heads.

[cook_dw]

I'd get me one of those 3/4 race cams..



In all seriousness.  My old 69 Camaro was a stock 350 flat tops, 186 heads (2.02/1.60's), Edelbrock Performer intake, Comp Cams 280 dura / 0.480" lift and a Holley Ultra HP 750 mech secs carb.  Stock ignition and it put down 276hp and 315tq to the tires through a M20 & 12 bolt with 3.55 gears.  It ran constant 13.2 - 13.8 depending on the driver in the 1/4.  Trap was right at 100mph.  Ran great on the street and drove that car everywhere.  Just not on the interstate.  I actually dyno'd the car myself to have it dead nuts at 12.5 on A/F at WOT but on the track it was lean so I bumped the jets 2 sizes and it ran its best.  Worthless 2 cents.

[Tinkerr]

Set of Double Hump heads will make all the difference 327/300 had 1.94" intake 1.60"exhaust valves... 327/365 had 2.02" intake 1.60 exhaust valves... 327/210 had 1.72 intake 1.50 exhaust valves.

[Kelley W King]

I agree that the heads are the holdback now. With what you have done so far I think I would go with the 2.02 valve heads. They would look original and are not that hard to find. Get someone to do a good valve job before installing and you should feel the difference.

[Stingr69]

Just my perspective - The stock 327 is great when used to cruise around.  To increase power above that level you will need to move the torque up higher in the RPM power band.  That involves adding compression and a cam intended for a higher RPM torque peak.  Heads with smaller combustion chambers and a new cam/lifters would be required at a minimum.  If you want to stay with the period correct look, the double hump heads make sense.  Aftermarket heads will be cost effective and work even better but you loose the "period correct" look.  Cam choice is another judgement call.  The factory 327/350 HP cam is an easy choice here but you have plenty of other options.  If I were in your shoes, I would do this change without any hesitation.

[bcmiller]

It all depends on how close to a stock look you want to maintain.

Bigger cam with appropriate valve train changes and better heads will help the most. Otherwise you are looking at a rebuild with better rods/pistons/crank and that will be a lot more money.

[69DuskBlueRS/Z28]

Brzezinski can do wonders with a set of heads.  Very happy with all the work he has done for me.  https://www.castheads.com/

[68L30]

I’ll concur with all the above when saying “heads”. Mine been a Day 2 L-30 since I first got it. Although I blueprinted the bottom end & added forged slugs, most of the gains came from the deck & above. I cut into a pair of 462’s. The chambers were cc’d, ports cleaned, matched and bowl work done. I went with titanium race flow valves, bigger springs, screw in studs, guide plates. I used a Z intake, minus the plenum, again ported and matched to the heads. On top of that is a 1” spacer & a 780 Holley. This all works sitting on a zero deck block, as cast it was way out of spec. Camshaft, critical….I’ve run a bunch. Currently running a hyd roller along with roller tip rockers ( fit under stock covers) .

[Fred Mertz]

I replaced mine with a GMPP 383/425 crate engine.

[lynnbilodeau]

Replace the heads.   Of course, doing one mod sometimes requires modding other things to match up.
Vintage heads with 1.94 or 2.02 valves are not that cheap any more.   After you pay someone to mod them, you will have spent as much as if you just bought a new set of AFR heads.  Go with the smallest port volume they sell for sbc.  I think that is 195.   You can buy them ready to run for about $2k.
If it were me, I would go with a hydraulic roller cam.  I put a low rpm motor in my 49 Studebaker dump truck and even used a roller cam in it.  I don't want to worry about losing a lobe.  I know it adds some expense, but I think the long term rewards are worth it.

[David K]

With all this being the quick fix is 5e heads, I would caution you about replacing just the heads unless you know exactly how many miles the engine has on it. You might end up going backwards instead of forwards.

[Stingr69]

Trick Flow Specialties makes a nice aluminum version of the "double hump" factory heads.  They have the same casting marks so they look stock but flow way better than any ported factory head. They have them either with or without the accessory bolt holes in the ends to keep the "look" right depending on the year of the car. This would be the place to use them. 

Roller cams are nice too but the cost increase for all the required parts/upgrades is around $1000 over a flat tappet build. A stroker mod would be more cost effective.  Maybe do both. 

[cook_dw]

0.540" lift springs

Trick Flow 30210002 Link



0.600" lift springs

Trick Flow 30210003 Link