Thoughts on this combination for stock?

66 BELAIR · 03-19-2010, 07:40 PM

1966 Chevrolet 2dr Belair auto 427-390 hp,looking for input,good and bad,and also in your opinion, is the intake manifold and valve sizes going to be a problem,since they are the same as the 396-325 hp.thank you. 66BELAIR.

GTX JOHN · 03-19-2010, 11:33 PM

I think the 396 would be much better....31CI less and 65Hp less. However we race Mopars. Kids satellite has 400CI , Big 850 Carb , 480 lift cam, Big valve heads and is 298HP. It would be tough to spot him over 1000Lbs in G/sa with only 27 extra CI.

There are a lot of small block combination for that body that I have seem run very competitive for years. Probably much less expensive and easier to maintain if you are just starting out.

Jeff Lee · 03-20-2010, 11:08 AM

Steve Hauter fought that for years. Seems to know what he's doing. He finally gave up, dropped a 396 / 325 in it and picked up a ton on the ladder.

66 BELAIR · 03-20-2010, 08:02 PM

Thank you for your replies.I did look at the 396 combo,the camshaft looked weak.I thought the 427 combo looked better,much better cam.I did question the intake and valve sizes feeding the extra cubes.Would this have been the problem for Steve Hauter not running far enough under the index,compared to the 396?

Chuck Norton · 03-20-2010, 08:42 PM

Just like every other combination in the book, the most critical element is the horsepower that is assigned to the combination. A vigorous letter writing campaign can sometimes result in a change in the factored horsepower. A significant number of the combinations at the top of the qualifying sheets are there because they have been assigned favorable ratings, in some cases many years after they were produced and raced at their factory ratings with lackluster results. Just imagine how good that 427 would look if a stroke of the magic pen wiped fifty or sixty horsepower away. It has happened.

Aubrey N Bruneau · 03-21-2010, 01:03 PM

I agree with the "writing letters" for a HP adjustment. In the past, I was the only guy with my combination, who wrote in... both letters were responded to with an adjustment.

One would think that given the heads and such are basically the same for the 396 as the 427, the most logical difference would be relative to their differences in displacement ?
like a 30 HP difference maybe ?

I dunno
just thinking out loud

Biscayne · 03-22-2010, 10:51 PM

The 390 h.p. motor is already factored at 370 h.p. So not sure how much more it will be dropped. I run the 69 427 335 h.p. combo in a 69 Biscayne. I am pretty happy with this combo so far. Have only run it half a season. But so far so good. It's the same motor as a 427 390 h.p. with the 396 325 h.p. cam. If you need any help with that combo, let me know. I may be able to help you out, with suspension, motor, trans, gear, etc. Good luck with it.

03-19-2010, 07:40 PM	#1
66 BELAIR Junior Member Join Date: Apr 2007 Posts: 13 Likes: 0 Liked 0 Times in 0 Posts	Thoughts on this combination for stock? 1966 Chevrolet 2dr Belair auto 427-390 hp,looking for input,good and bad,and also in your opinion, is the intake manifold and valve sizes going to be a problem,since they are the same as the 396-325 hp.thank you. 66BELAIR.

03-19-2010, 11:33 PM	#2
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,545 Likes: 2,242 Liked 1,887 Times in 580 Posts	Re: Thoughts on this combination for stock? I think the 396 would be much better....31CI less and 65Hp less. However we race Mopars. Kids satellite has 400CI , Big 850 Carb , 480 lift cam, Big valve heads and is 298HP. It would be tough to spot him over 1000Lbs in G/sa with only 27 extra CI. There are a lot of small block combination for that body that I have seem run very competitive for years. Probably much less expensive and easier to maintain if you are just starting out. Last edited by GTX JOHN; 03-20-2010 at 04:01 AM.

03-20-2010, 11:08 AM	#3
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 2 Times in 2 Posts	Re: Thoughts on this combination for stock? Steve Hauter fought that for years. Seems to know what he's doing. He finally gave up, dropped a 396 / 325 in it and picked up a ton on the ladder. __________________ Jeff Lee 7494 D/S '70 AMX

03-20-2010, 08:02 PM	#4
66 BELAIR Junior Member Join Date: Apr 2007 Posts: 13 Likes: 0 Liked 0 Times in 0 Posts	Re: Thoughts on this combination for stock? Thank you for your replies.I did look at the 396 combo,the camshaft looked weak.I thought the 427 combo looked better,much better cam.I did question the intake and valve sizes feeding the extra cubes.Would this have been the problem for Steve Hauter not running far enough under the index,compared to the 396?

03-20-2010, 08:42 PM	#5
Chuck Norton Member Join Date: Dec 2001 Location: Covina, CA Posts: 470 Likes: 81 Liked 69 Times in 15 Posts	Re: Thoughts on this combination for stock? Just like every other combination in the book, the most critical element is the horsepower that is assigned to the combination. A vigorous letter writing campaign can sometimes result in a change in the factored horsepower. A significant number of the combinations at the top of the qualifying sheets are there because they have been assigned favorable ratings, in some cases many years after they were produced and raced at their factory ratings with lackluster results. Just imagine how good that 427 would look if a stroke of the magic pen wiped fifty or sixty horsepower away. It has happened.

03-21-2010, 01:03 PM	#6
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Re: Thoughts on this combination for stock? I agree with the "writing letters" for a HP adjustment. In the past, I was the only guy with my combination, who wrote in... both letters were responded to with an adjustment. One would think that given the heads and such are basically the same for the 396 as the 427, the most logical difference would be relative to their differences in displacement ? like a 30 HP difference maybe ? I dunno just thinking out loud __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409

03-22-2010, 10:51 PM	#7
Biscayne Junior Member Join Date: Jul 2005 Location: Md Posts: 93 Likes: 0 Liked 2 Times in 2 Posts	Re: Thoughts on this combination for stock? The 390 h.p. motor is already factored at 370 h.p. So not sure how much more it will be dropped. I run the 69 427 335 h.p. combo in a 69 Biscayne. I am pretty happy with this combo so far. Have only run it half a season. But so far so good. It's the same motor as a 427 390 h.p. with the 396 325 h.p. cam. If you need any help with that combo, let me know. I may be able to help you out, with suspension, motor, trans, gear, etc. Good luck with it. __________________ Scott Chalk 1226 I/SA