455 vs. 403 and rebuilds

briancrittendonii · 07-29-2006, 08:09 PM

How much differance will there be between a 403 and 455. Will it be crazy noticable on the strip? and the biggest question of them all is what are the best performance parts to use for the 455. PLEASE I need names.

AggieOlds · 08-03-2006, 04:31 PM

Size does matter, 455. One of the major performance distributors of Olds 455 parts and complete motors, Mondello Performance Products, www.mondellotwister.com.

Oldsguy · 08-04-2006, 04:46 AM

Although you would find that Mondello is not that highly rated in some Oldsmobile performance circles. I agree with AggieOlds, more and bigger is better. HOWEVER, you will find a lot of staunch supporters of the 403, many of the "Burt Reynolds" Firebirds cars had the Olds 403 and they are good engines.

badd andy · 08-04-2006, 08:13 AM

Consistently Spin A 403 Over 5500 Rpm,and It Will Disintegrate.

Fishydoo · 10-02-2006, 02:15 AM

Hi , i'm new to the forum. Just interested what rev's you think a stock 455 crank can handle? Eng is a '72 model.

69deltaconvert · 11-07-2006, 10:19 AM

I have seen 403's send the crank and rods through the oil pan if you rap them up to around 8500 was where the I saw went kaput. But people do make engine girdles and lighter rotating assemblies to prevent this. I would say best bang for the buck is a 455 but others will disagree. Fishydoo keep it under 5500 to tell you the truth if its all stock I would keep it below 4500 but thats me.

Redog · 11-07-2006, 11:22 PM

I've done a lot a reseach on this, and a 455 is good if you can get HD srpings for the car in question. The 455 adds about 200 lbs to the front end over a SBO.

The 350 can be bulit-up the same as a 455. The 350 will rev a bit higher and quicker than the 455, but the 455 has more torque that a 350. However, the build-up of both motors is about the same. Plus remember this, the best thing about a SBO is the BB heads can put onto a SB engine.

Personally I was a bit bummed to find out that the 350 is a better build for me. I wanted the bragging rights of saying I have a 455 (or a 7.5 liter) motor or even the 403 (6.6 liter) motor, but with putting a 455 in my project, I need about 50 or so more HP to get the same numbers in the 1/4 mile

Kennybill · 11-12-2006, 10:28 PM

Oh Boy, here we go. What kind model of Olds and what engine is in it now? I have raced 350's/403's/425's/455's. NO OLDS ENGINE can live at 8500 RPM's. Now I will tell u what I know. I have bracket raced a 403 for 4 years. Engine is pretty mild, stock #5 heads are holding it back. 12:90's@105.85, 60's only 1:80's. Shift @5500, comes through @ 5150. A guy @ realoldspower has 850 runs on a 403 that goes 11:90's, shifts @ 6300 and through the traps @6500. I have seen more 455's spun bearings/rods through the block than the 403. I have never personally seen a 403 hurt yet. In my "main" race car I run a 425, I like them better than the 455. Whatever fits the best use. Put a big oil pan on it whichever engine u use. Ken

Oldsguy · 11-13-2006, 05:50 AM

Kenny, those are some beautiful B bodies, especially the '69 98!

Kennybill · 11-13-2006, 11:23 AM

Thank You, Both 98's are 4-door 1967 LS'. Green one is a 71 Delta

Oldsguy · 11-13-2006, 11:38 AM

DUH! I should have known that.............

Eightupman · 11-13-2006, 11:50 AM

Quote:

Originally Posted by Oldsguy

Although you would find that Mondello is not that highly rated in some Oldsmobile performance circles. I agree with AggieOlds, more and bigger is better. HOWEVER, you will find a lot of staunch supporters of the 403, many of the "Burt Reynolds" Firebirds cars had the Olds 403 and they are good engines.

I have not heard from anyone in any of these forums that hold Mondello in high regard. Evryone (that I have talked to) says his stuff is overpriced junk. There is another company that I read of in one of these forums that is about to introduce some Olds Hi-perf parts.

texasred · 11-15-2006, 05:28 AM

Quote:

Originally Posted by Eightupman

I have not heard from anyone in any of these forums that hold Mondello in high regard. Evryone (that I have talked to) says his stuff is overpriced junk. There is another company that I read of in one of these forums that is about to introduce some Olds Hi-perf parts.

True enough on Mondello...but you need to visit www.realoldspower.com . There's already lots of companies already building Olds Hi-perf parts. You just can't buy them at Jeggs!

C.J.

olds 307 and 403 · 12-02-2006, 05:04 PM

The olds 455 is not a screamer with its big 3" mains. The 403 can spin just as high as a 455. The 403 has much better bore/stroke ratio, just the windowed mains hurt the extreme rpm ability.

07-29-2006, 08:09 PM	#1 (permalink)
briancrittendonii Junior Member Join Date: Jul 2006 Posts: 3	455 vs. 403 and rebuilds How much differance will there be between a 403 and 455. Will it be crazy noticable on the strip? and the biggest question of them all is what are the best performance parts to use for the 455. PLEASE I need names.

08-04-2006, 04:46 AM	#3 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 2,859	Although you would find that Mondello is not that highly rated in some Oldsmobile performance circles. I agree with AggieOlds, more and bigger is better. HOWEVER, you will find a lot of staunch supporters of the 403, many of the "Burt Reynolds" Firebirds cars had the Olds 403 and they are good engines. __________________ Dan '46 2 door

10-02-2006, 02:15 AM	#5 (permalink)
Fishydoo Junior Member Join Date: Oct 2006 Location: New Zealand Posts: 13	eng revs Hi , i'm new to the forum. Just interested what rev's you think a stock 455 crank can handle? Eng is a '72 model.

11-07-2006, 11:22 PM	#7 (permalink)
Redog Alero Chapter Secretary Join Date: Aug 2006 Location: Newtown, PA Posts: 699	I've done a lot a reseach on this, and a 455 is good if you can get HD srpings for the car in question. The 455 adds about 200 lbs to the front end over a SBO. The 350 can be bulit-up the same as a 455. The 350 will rev a bit higher and quicker than the 455, but the 455 has more torque that a 350. However, the build-up of both motors is about the same. Plus remember this, the best thing about a SBO is the BB heads can put onto a SB engine. Personally I was a bit bummed to find out that the 350 is a better build for me. I wanted the bragging rights of saying I have a 455 (or a 7.5 liter) motor or even the 403 (6.6 liter) motor, but with putting a 455 in my project, I need about 50 or so more HP to get the same numbers in the 1/4 mile __________________ Me 2000 Alero running 14's 1985 Delta 88 w/1968 350 rocket 2005 Nissan Altima (her's)

11-12-2006, 10:28 PM	#8 (permalink)
Kennybill Senior Member Join Date: Aug 2005 Location: Youngstown, Ohio Posts: 196	Oh Boy, here we go. What kind model of Olds and what engine is in it now? I have raced 350's/403's/425's/455's. NO OLDS ENGINE can live at 8500 RPM's. Now I will tell u what I know. I have bracket raced a 403 for 4 years. Engine is pretty mild, stock #5 heads are holding it back. 12:90's@105.85, 60's only 1:80's. Shift @5500, comes through @ 5150. A guy @ realoldspower has 850 runs on a 403 that goes 11:90's, shifts @ 6300 and through the traps @6500. I have seen more 455's spun bearings/rods through the block than the 403. I have never personally seen a 403 hurt yet. In my "main" race car I run a 425, I like them better than the 455. Whatever fits the best use. Put a big oil pan on it whichever engine u use. Ken __________________ A man has to know his limitations, especially with an Oldsmobile

08-03-2006, 04:31 PM	#2 (permalink)
AggieOlds Junior Member Join Date: Feb 2006 Location: Houston, Texas Posts: 14	Size does matter, 455. One of the major performance distributors of Olds 455 parts and complete motors, Mondello Performance Products, www.mondellotwister.com.

08-04-2006, 08:13 AM	#4 (permalink)
badd andy Junior Member Join Date: Aug 2006 Posts: 20	Consistently Spin A 403 Over 5500 Rpm,and It Will Disintegrate.

11-07-2006, 10:19 AM	#6 (permalink)
69deltaconvert Member Join Date: Jul 2006 Location: Seattle Posts: 66	I have seen 403's send the crank and rods through the oil pan if you rap them up to around 8500 was where the I saw went kaput. But people do make engine girdles and lighter rotating assemblies to prevent this. I would say best bang for the buck is a 455 but others will disagree. Fishydoo keep it under 5500 to tell you the truth if its all stock I would keep it below 4500 but thats me.

11-13-2006, 05:50 AM	#9 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 2,859	Kenny, those are some beautiful B bodies, especially the '69 98! __________________ Dan '46 2 door

11-13-2006, 11:23 AM	#10 (permalink)
Kennybill Senior Member Join Date: Aug 2005 Location: Youngstown, Ohio Posts: 196	Thank You, Both 98's are 4-door 1967 LS'. Green one is a 71 Delta __________________ A man has to know his limitations, especially with an Oldsmobile

11-13-2006, 11:38 AM	#11 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 2,859	DUH! I should have known that............. __________________ Dan '46 2 door

12-02-2006, 05:04 PM	#14 (permalink)
olds 307 and 403 Junior Member Join Date: Dec 2006 Posts: 4	The olds 455 is not a screamer with its big 3" mains. The 403 can spin just as high as a 455. The 403 has much better bore/stroke ratio, just the windowed mains hurt the extreme rpm ability.

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