69 L36 427 swap to aluminum heads?

[Don W.]

Has anyone had successful performance improvements by putting their matching number cast iron heads into storage and upgrading to one of the current aluminum head aftermarket options? I have a 2nd flight car and I've taken it as far as it will go and I'm looking for some performance enhancements that can be returned to original configuration at a later date.
Thank you,
Don

[Jim D.]

Re: 69 L36 427 swap to aluminum heads?

I'm considering doing the same. In my past experience involving SB Chevys, SB Fords and BB block Fords, ANY aftermarket aluminum head is far superior the best OEM head available. My L-78 65 has a L-72 installed by GM in 1970 so #'s matching means nothing to me.

[Don W.]

Re: 69 L36 427 swap to aluminum heads?

mine is a 390HP/427 with auto and 3.08 in the rear axle and dyno's at 260 Rear wheel HP and I'm trying to get it to something more peppy and fun to drive than my 2006 Honda Pilot

[Joe L.]

Re: 69 L36 427 swap to aluminum heads?

mine is a 390HP/427 with auto and 3.08 in the rear axle and dyno's at 260 Rear wheel HP and I'm trying to get it to something more peppy and fun to drive than my 2006 Honda Pilot

Don-------


If you make this change, you'll have to find an aluminum head with oval ports, about 110 cc combustion chambers, and open exhaust cross-over ports (assuming you want an operable auto choke). That will limit your candidates. However, there are heads out there that will meet these requirements. GMPP does not have any currently that meet all three criteria. However, they do have two that meet the criteria except for an open exhaust cross-over. These are GM #19331424 (2.19" intake valves) or GM #19331425 (2.25" intake valves). It might be possible to open up the exhaust cross-over on these heads.

[Don W.]

Re: 69 L36 427 swap to aluminum heads?

Thank you Joe for the information. Perhaps it would be better to have my engine removed and stored on a engine stand and find a Chevrolet Performance LS7 427 that fits in the car? Don

http://www.jegs.com/i/Chevrolet-Perf...03238/10002/-1

[Jim D.]

Re: 69 L36 427 swap to aluminum heads?

If you want to change the engine but still be somewhat original, here's a much better/bolt-in option than LS7 - http://blueprintengines.com/index.ph...ads-roller-cam

[Joe L.]

Re: 69 L36 427 swap to aluminum heads?

Thank you Joe for the information. Perhaps it would be better to have my engine removed and stored on a engine stand and find a Chevrolet Performance LS7 427 that fits in the car? Don

http://www.jegs.com/i/Chevrolet-Perf...03238/10002/-1

Don------

The LS engine will provide excellent performance. However, as good as these engines are, I would not recommend one for you. That's because installing one of these engines is also going to require a lot of other mods to the car, some of which might not be easily reversible. By staying within an original engine architecture, the conversion is greatly simplified.

By the way, Edelbrock has some heads available that meet all of the criteria I mentioned above.

Want even more performance in conjunction with a head swap? Install an hydraulic roller cam with intake and exhaust duration about the same as the L-36 cam but with more lift.

[Joe L.]

Re: 69 L36 427 swap to aluminum heads?

If you want to change the engine but still be somewhat original, here's a much better/bolt-in option than LS7 - http://blueprintengines.com/index.ph...ads-roller-cam

Jim------

There's such a thing as too much power and torque in a Corvette. A 1963-82 Corvette driveline is not really all that stout. If one adds too much power and, especially, torque to a Corvette, then one has to also modify and beef-up the driveline. Folks don't usually want to get involved with what that takes. I don't blame them; I wouldn't want to, either. 496 cubic inches equals a LOT of torque.

As it is, big blocks are really marginal in a Corvette chassis and driveline designed around small blocks.

[Don W.]

Re: 69 L36 427 swap to aluminum heads?

Thank you Joe for your guidance and sound technical judgement...Don

[Don W.]

Re: 69 L36 427 swap to aluminum heads?

Does anyone know the Edelbrock info or part # for heads that meet these 3 criteria: aluminum head with oval ports, about 110 cc combustion chambers, and open exhaust cross-over ports (assuming you want an operable auto choke)? The open exhaust cross over is needed to support the q-Jet choke and there is no electric choke option for the q-jet. I checked edelbrock's web site and didn't see any info discussing cross-over exhaust ports....Don

[Jim D.]

Re: 69 L36 427 swap to aluminum heads?

Edelbrock has E-Street, Performer and Performer RPM heads that meet your criteria.

[Joe L.]

Re: 69 L36 427 swap to aluminum heads?

Does anyone know the Edelbrock info or part # for heads that meet these 3 criteria: aluminum head with oval ports, about 110 cc combustion chambers, and open exhaust cross-over ports (assuming you want an operable auto choke)? The open exhaust cross over is needed to support the q-Jet choke and there is no electric choke option for the q-jet. I checked edelbrock's web site and didn't see any info discussing cross-over exhaust ports....Don

Don------


There are quite a few Edelbrock part numbers for suitable heads. It depends upon whether you want to buy bare or complete heads. If complete, it depends upon whether you want installed valve springs for a flat tappet cam or an hydraulic roller. Look for "Performer 454-O" or "Performer RPM 454-O".

By the way, Edelbrock heads are very high quality and completely manufactured in the USA. They are also the company that manufactures the GMPP cylinder heads.

[Jim D.]

Re: 69 L36 427 swap to aluminum heads?

The E-Street Oval #50459 would probably be a better match for the OP's mild, hyd. cammed BB. No need to get heads that make power in the RPM range that his motor can't see.

[Joe L.]

Re: 69 L36 427 swap to aluminum heads?

The E-Street Oval #50459 would probably be a better match for the OP's mild, hyd. cammed BB. No need to get heads that make power in the RPM range that his motor can't see.

Jim-------


Yes, the Edelbrock E-Street heads will work fine for this application. However, either the E-Street, Performer, or Performer RPM series heads are all designed for engine operation up to 5,500 RPM which is entirely consistent with the RPM range of the L-36 engine.

[Don W.]

Re: 69 L36 427 swap to aluminum heads?

Hi Joe...I will probably go all out and install a hydraulic roller cam with similar duration to the stock cam and more lift. Let me know if that narrows down the selection...Don