Author Topic: '79 403 Advice  (Read 600 times)

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Offline Gordonfan24

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'79 403 Advice
« on: June 03, 2014, 06:40:36 PM »
Hello there guys and gals. Opinions are surely going to vary but I welcome all who would be so kind as to give me theirs. I am not a novice nor am I an expert. I am, however, quite unfamiliar with Olds engines and their attributes or weaknesses.

I've got a 403 block. It's already .030 over and my machinist is going to see if it will clean up to .040. because the cylinders looked really nice except for one where water had sit in it for an unknown amount of time causing as of yet an unknown amount of pitting of the cylinder wall.
I'd like to keep it to where I can drive it regularly but have around 400-425 hp.
I'm looking for specific combos that anyone has used to achieve what I'm after. Is it even possible. Money is not an issue. I want it right and I want it tight. Dependable, durable and STRONG. Thanks in advance for any replies.

Offline hada76

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Re: '79 403 Advice
« Reply #1 on: June 03, 2014, 09:23:32 PM »
have heard the 403 can be modded, but 400+hp is at the very top of the scale
some good info here
https://sites.google.com/site/ksmsinc/technical-info/title-3/olds-403-engine-info
'76 T/A 455 4sp   sold
'78 T/A Y88 auto  sold
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'70 Z/28 4sp

jeff

Offline Gordonfan24

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Re: '79 403 Advice
« Reply #2 on: June 03, 2014, 10:34:46 PM »
Very interesting read. Thank you sir!  ;D

Offline Aus78Formula

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Re: '79 403 Advice
« Reply #3 on: June 04, 2014, 02:10:30 AM »
400-450hp isn't that hard to achieve, realistically its around the same limit for the same era Pontiac 400 that start cracking, so that's a non argument. Grab a bolt on halo girdle for cheap insurance, KB pistons and stock heads port matched and opened up with bigger valves, cam to match final setup. A shaker TA will use the Performer intake unless you like having dramas so that limits breathing somewhat. Headers are also an option. I have a 380hp\480tq 403 that uses the lower intake and Thornton exhausts manifolds and mild cam so left some power still on the table. I like it simply to be different and not a chev. It's a fairly standard 403 build these days, a search will bring up  plenty and saves retyping.