Which Small Block Olds is Better

78cutlass · February 5th, 2008, 05:52 PM

If you wanted to build a "warmed over daily driver" small block Olds for a '78 Cutlass, which one of these two motors would be the better choice (explanations welcomed):

'69 Olds 350 with #5 heads

Olds 403 with #5 heads

Olds64 · February 6th, 2008, 11:25 AM

If you are just building a daily driver you might be happier with the 403. It has a little bit more displacement and you will run the same heads on either engine so that won't be an issue. The big isssue with 403s is that they have windowed mains so it makes it more difficult to rev them higher. However, if you are just going to have a weekend warrior you probably won't red line the engine often.

Then again, I have heard 403s have cooling issues since they have siamese cylinders. This can be overcome with a radiator and fan in good working condition though.

78cutlass · February 6th, 2008, 12:12 PM

Olds64,
Thanks for your input. If I went with the 403, I'd pick a torque cam in the 1400-4800 RPM range. I'd strive for a compression in the 9.5 to 1 or 10.1 range in order to keep things "pump-gas friendly". The #5's would allow me to achieve that compression easily. Thank you.

78cutlass

Olds64 · February 6th, 2008, 05:47 PM

Well, don't base your decision solely on what I say. The 350 has merits too. Keep this post near the top and I am sure you will get alot more opinions. It is always good to get as much info as possible.

88 coupe · February 6th, 2008, 11:22 PM

Quote:

Originally Posted by Olds64

........ The big isssue with 403s is that they have windowed mains ........

I have also heard that. In reality, it would depend what power level is being discussed.

For a "warmed over daily driver" windowed mains should not be an issue.

Quote:

........ Then again, I have heard 403s have cooling issues ........

I have only heard that from one person. Looks like you have the 403 confused with a 400 Chev.

Norm

78cutlass · February 7th, 2008, 12:38 AM

88 Coupe,
I'd be content with 350 HP/350 FT LB TQ Olds small block motor as a daily driver. I think the '69 W-31 350, which was the "top dog" 350 motor, was a 325 HP/360 TQ motor. The regular '69 4-barrel 350 was about 310 HP/390 TQ! For a street driven car I'd be more interested in having a torquey motor than anything else, especially with the fact that a '78 Cutlass isn't a light car.

88 coupe · February 7th, 2008, 02:03 AM

Quote:

Originally Posted by 78cutlass

88 Coupe ........

78cutlass.

Quote:

Originally Posted by 78cutlass

........ I'd be content with ........

I do not know anything about all those numbers, and I certainly do not need BOLD fonts, to aid my reading comprehension.

Quote:

Originally Posted by 78cutlass

........ For a street driven car I'd be more interested ........

I'm sure you will be happy with whatever you choose.

Quote:

Originally Posted by 78cutlass

........ a '78 Cutlass isn't a light car.

Thank you for telling me, but I already know how heavy it is.

Now, what was your point?

Norm

f-85 · February 7th, 2008, 05:55 AM

Damn Norm somebaody having a bad day? Or you probably already know that.

Josh

Olds64 · February 7th, 2008, 06:23 AM

Quote:

However, if you are just going to have a weekend warrior you probably won't red line the engine often.

Thus he won't have to worry about the windowed mains.

Quote:

I have heard 403s have cooling issues

Key words being "I have heard." If you really want to know where I heard then you can go over to Oldspower.com and do some reading. Those guys there seem to know their stuff.

tonycpe · February 7th, 2008, 07:22 AM

the people at oldspower seem to have problems installing a rear view mirror.

78cutlass · February 7th, 2008, 11:28 AM

Hmm, which one will I use:

'69 Olds 350 with #5 heads

Olds 403 with #5's

I think I'll build the '69 as a "warmed-over daily driver" for my '78 Cutlass

captjim · February 7th, 2008, 02:24 PM

Quote:

Originally Posted by tonycpe

the people at oldspower seem to have problems installing a rear view mirror.

That's not nice! It's funny, but not nice!!!

Couple of things. First, those high torque 350s are high compression engines, in the 10.25 to 1 range, not really practical on today's pump gas. Second, as far as Oldsmobiles go, a 78 Cutlass is about the LIGHTEST car they made. I am no great 403 fan, but for a mild build it will work fine. Do your research on pistons and heads, you can easily end up with too much CR using the #5s. Personally, if I was going to do a 403, I would use the 4A head and the KBs, cr ends up around 9.6, perfect for pump gas. The 4As already have 1/2" bolt holes, correct dowel pin sizes, and big intake valves. A little work on the exhaust and you are good to go. If it is your first build, IMHO the 350 is easier and a little more forgiving.

78cutlass · February 7th, 2008, 02:58 PM

a 403 build sure sounds tempting. I'll need to find one first.

78cutlass · February 7th, 2008, 03:01 PM

captjim, you brought up some good points....

78cutlass · February 7th, 2008, 03:07 PM

I agree, a compression ratio of about 9.5 to 1 or 9.6 as you mentioned would be perfect for a street car.

88 coupe · February 7th, 2008, 08:58 PM

Quote:

Originally Posted by f-85

........ somebaody having a bad day? ........

No.

I sent a simple reply, to a message with my name on it, followed by a question regarding its content. If it did not have my name on it, I would have ignored it.

What did you read into my post, that I did not write into it?

Norm

88 coupe · February 7th, 2008, 09:39 PM

Quote:

Originally Posted by Olds64

........ Key words being "I have heard." ........

Kinda like when a "redneck" starts his story with "y'all ain't gonna believe this s**t".

Quote:

Originally Posted by Olds64

........ you can go over to Oldspower.com and do some reading ........

Been there, done that.

You can go over to Real Oldspower.com and do some reading.

Quote:

Originally Posted by Olds64

........ Those guys there seem to know their stuff.

Key words being "seem to know".

Quote:

Originally Posted by tonycpe

the people at oldspower seem to have problems installing a rear view mirror.

Nuff said.

Norm

Olds64 · February 8th, 2008, 06:23 AM

February 5th, 2008, 05:52 PM	#1 (permalink)
78cutlass 78cutlass Join Date: Jan 2008 Location: Florida Posts: 100	Which Small Block Olds is Better If you wanted to build a "warmed over daily driver" small block Olds for a '78 Cutlass, which one of these two motors would be the better choice (explanations welcomed): '69 Olds 350 with #5 heads Olds 403 with #5 heads

February 6th, 2008, 11:25 AM	#2 (permalink)
Olds64 Landyacht Club President Join Date: Jul 2007 Location: Lawton, OK Posts: 4,286	If you are just building a daily driver you might be happier with the 403. It has a little bit more displacement and you will run the same heads on either engine so that won't be an issue. The big isssue with 403s is that they have windowed mains so it makes it more difficult to rev them higher. However, if you are just going to have a weekend warrior you probably won't red line the engine often. Then again, I have heard 403s have cooling issues since they have siamese cylinders. This can be overcome with a radiator and fan in good working condition though. __________________ Ferris, my father loves this car more than life itself... Apparently, you don't understand! Ferris, he never drives it! He just rubs it with a diaper! Cameron Frye Ferris Bueller's Day Off 1986

February 6th, 2008, 05:47 PM	#4 (permalink)
Olds64 Landyacht Club President Join Date: Jul 2007 Location: Lawton, OK Posts: 4,286	Well, don't base your decision solely on what I say. The 350 has merits too. Keep this post near the top and I am sure you will get alot more opinions. It is always good to get as much info as possible. __________________ Ferris, my father loves this car more than life itself... Apparently, you don't understand! Ferris, he never drives it! He just rubs it with a diaper! Cameron Frye Ferris Bueller's Day Off 1986

February 7th, 2008, 12:38 AM	#6 (permalink)
78cutlass 78cutlass Join Date: Jan 2008 Location: Florida Posts: 100	88 Coupe, I'd be content with 350 HP/350 FT LB TQ Olds small block motor as a daily driver. I think the '69 W-31 350, which was the "top dog" 350 motor, was a 325 HP/360 TQ motor. The regular '69 4-barrel 350 was about 310 HP/390 TQ! For a street driven car I'd be more interested in having a torquey motor than anything else, especially with the fact that a '78 Cutlass isn't a light car. Last edited by 78cutlass; February 7th, 2008 at 12:47 AM..

February 7th, 2008, 07:22 AM	#10 (permalink)
tonycpe Registered User Join Date: Jan 2008 Location: Cheboygan, Michigan Posts: 49	the people at oldspower seem to have problems installing a rear view mirror. __________________ Old Fogey Racing Ltd.

February 6th, 2008, 12:12 PM	#3 (permalink)
78cutlass 78cutlass Join Date: Jan 2008 Location: Florida Posts: 100	Olds64, Thanks for your input. If I went with the 403, I'd pick a torque cam in the 1400-4800 RPM range. I'd strive for a compression in the 9.5 to 1 or 10.1 range in order to keep things "pump-gas friendly". The #5's would allow me to achieve that compression easily. Thank you. 78cutlass

February 7th, 2008, 05:55 AM	#8 (permalink)
f-85 Registered User Join Date: Aug 2007 Location: Yorkville,il Posts: 279	Damn Norm somebaody having a bad day? Or you probably already know that. Josh

February 7th, 2008, 11:28 AM	#11 (permalink)
78cutlass 78cutlass Join Date: Jan 2008 Location: Florida Posts: 100	Hmm, which one will I use: '69 Olds 350 with #5 heads Olds 403 with #5's I think I'll build the '69 as a "warmed-over daily driver" for my '78 Cutlass

February 7th, 2008, 02:58 PM	#13 (permalink)
78cutlass 78cutlass Join Date: Jan 2008 Location: Florida Posts: 100	a 403 build sure sounds tempting. I'll need to find one first.

February 7th, 2008, 03:01 PM	#14 (permalink)
78cutlass 78cutlass Join Date: Jan 2008 Location: Florida Posts: 100	captjim, you brought up some good points....

February 7th, 2008, 03:07 PM	#15 (permalink)
78cutlass 78cutlass Join Date: Jan 2008 Location: Florida Posts: 100	I agree, a compression ratio of about 9.5 to 1 or 9.6 as you mentioned would be perfect for a street car.

February 8th, 2008, 06:23 AM	#18 (permalink)
Olds64 Landyacht Club President Join Date: Jul 2007 Location: Lawton, OK Posts: 4,286	__________________ Ferris, my father loves this car more than life itself... Apparently, you don't understand! Ferris, he never drives it! He just rubs it with a diaper! Cameron Frye Ferris Bueller's Day Off 1986

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