rfn026

Horsepower is what you brag about. Torque is what you drive.

Richard Newton
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65Vett04

My 65's L76 (365) runs fine on 93 octane, so find the best car you can and enjoy it.

Avispa

Don't do that to an original motor car, except perhaps some valve bowl cleanup work. You never know when you're about to break through to the water jacket porting 50 year old castings. The cam you're going to need to get to 500 HP with stock heads is going to make the motor a lumpy, ill-mannered, tempermental beast, and if you are planning to run stock exhaust manifolds, forget it. A stock L79 will make you very happy.

If its a NOM car, just go buy a 383 roller cam motor and be done with it.

Easy Rhino

I think that perhaps for a person more used to modern engines but feels the need for more speed the L79 may be the way to go. For just cruising, any of them are fine, even the 250 and 300 hp versions.

I also agree that the L76 and fuelie may have been more interesting to Bubba and his buddies, but it varies with the individual car.

In keeping with the state of the technology and era of the car, I feel that the L76 is a good match, particularly with low rear gears, and no power or comfort accessories. Raw in nature, and requires some maintenance effort. The fuelie, too.

It all depends on what you want it for.

You gotta drive your own drive - not someone else's drive.

hokie04

I had a 300hp with a 3:55 rear and it was pretty quick plus it would run fine one any grade gas. It didn't require adjustments all the time and could sit in traffic all day long at 180 degrees. Just depends on how you want to use the car.

gilbybarr

I have a 300 hp in the '65. Great engine, smooth, not lumpy, great power. The key isn't so much choosing the HP, its choosing the right car, condition, history, etc.

alexandervdr

consider you personal driving style preference too. Max torque for standard 250/300/350/365 is roughly the same, but they deliver it at increasing rpm. Or put differently: for identical torque, you get it at lower rpm in a 250hp compared to a 365hp.I had a 365hp solid lifter, and I did not like it , while others who are more into intimidating exhaust/engine sound and speed will adore it.
If you are of the 'relax' type, then going lower in hp may actually please you more than you would think

65tripleblack

Have you ever built a 327 with ported double humps that made 500 HP? Seems impossible, even with a huge cam.

Mine made 370 RWHP with a 250/250 solid roller, 750 DP, open headers, and .610 lift. I ported the shlt out of those heads all the way to 185cc intake runners.

I don't think those heads are capable of 500 HP,,,,,,,,unless..............some very trick bronze brazing and numerical controlled machine work is done to them.

I have aluminum 205 cc heads on it now, and it makes 414 RWHP. Which is ?????????? flywheel HP.

Gary's '66

True, true, then there's gearing, tires, etc. but the OP was asking about "high horse power motors" which, his expert advisers misinformed him of.

Slowhand63

Curious to hear why some (most?) would prefer a 350 over a 365?

Revfan

You said 65-67... the 365 was on its way out in 65 and not offered in 66-67.

So, I think everyone is "assuming" you are referring to the main choices of 300/350 for 66-67.

Gary's '66

Both are great motors, the main difference being that the 365 hp has solid lifters, which, as pointed out was ended in '65 where as the 350 hp is hydraulic for '66 & '67. Actually I think most would prefer the 365 hp motor. I know I would, 'cause its got more ponies.

Easy Rhino

Some folks may not want to fool with solid lifters.

rfn026

I have a big horsepower 350 in my old C4. When I back out of the garage at Homestead people think the motor is broken We're talking seriously rough and lumpy. Then when I come down the front straight at 8000 rpm they love the sound.

I just know I would never want to drive the C4 more than 5 miles on the street. That's why I have a 283 Powerglide in my '58.

Richard Newton

rayvaflav

When I was shopping for a '66 coupe I reluctantly drove an OM 300hp. I was sold on the 300hp 327, I would rather have a 350hp with the hydraulic lifters (sorry, I simply want to assemble it and then never touch it again) but I was really surprised how useable the 300hp mill is.

Ray

Revfan

Agreed.
For my purposes, it does everything I need.

66since71

A "proper" sports car should rev eagerly... 300 HP just doesn't. A 350 or 365 does.

Harry

Revfan

guess I don't have a proper sports car then... oh well.

TCracingCA

He hadn't quite landed on anything in particular, but had some advice, and no where in the opener did the OP list the components for his plan. Therefore I find 500hp very nice. Yes it would be hard to get it out of dinosaur heads, and using such would really require camming it up and that would be ridiculous, but a smart modern built engine in 327 size at that power level can run very sweet on the street! It is pushing the chassis, so mods would be needed there, but it is nice to have that kind of potential fun and respect factor! A few blips of the throttle and the little Nissans and Toyotas and generic Porsches go hide. It can be very satisfying!

TCracingCA

If you dyno'd your engine, it would be 500+ hp, if you are making 414RWHP! Thus when you talk L-75, L-76, L-79, or L-84, you are only talking about 260- maybe 295 RWHP tops!

Ps if you have an engine and just plan a rebuild with some added prep- then you are not looking for Ideal HP! HP is created by flowing and maximizing the potential at a specific Cubic Inch. Therefore i see the max with reliability and tractability for a 327 being maxed at around 500hp on dyno for the guys that are going out to buy some new heads, a new cam! Even the old school Iron Bowties Phase 2's can easily be ported with reliability to make 500hp. Fopr a perfect nostalgic build, I would use an Iron bowtie block and not a production one, unless it was one of the truly high quality ones! I would iron bowtie head it and pick the cam of choice as per what you are looking for and then hang stock looking components to that base and have something better than stock, if you aren't numbers matching! I would honestly rather have top GM Bowtie performance parts (blocks and heads etc.) than a numbers matching stock engine or a butchered numbers matching engine filled with non NOS components. The simple fact you would be paying big money to find original edge orfice lifters and 30-30 cams etc or the L-79 components mades me sneer at those guys claiming numbers matching!!! while they mention there comp cams, edlebrock crap this or that! It is getting to be a rarity to come across a numbers matching engine that was assembled with all NOS parts! Therefore as soon as that in your build changes, then why stop there!