i used to have an awesome, mildly built 403 olds in my 78 grand prix. the motor just kicked *** and wasn't mainstream, and i loved it. how ridiculously hard would it be to throw one in my 84 berlinetta 305?? i already have a 2 different trannys that would bolt up, but what about motor mounts and hood clearances? strut tower space? please don't tell me i'm stupid, this is just for giggles, msybe one day it'll be done.

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'84 Berlinetta, LG4, 700R-4, starwars interior, no major mods yet

 

I've got a Olds 455 outside that I have been giving some thought to. Don't feel alone man. The only thing that won't be possible is the headers I think. Unless you fab some up yourself. There have been guys who put 455 pontiacs in 3rd gen firebirds but they could not use headers like you could with a Chevy 454. I am not sure about the motor mounts yet. I am going to find that out. Hood clearance might be a problem unless you use a drop base aircleaner.

[This message has been edited by IROC315 (edited September 02, 2001).]

 

or a nice big cowl hood!!!

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'88 CAMARO 305
OPEN AIR ELEMENT
FLOWMASTER CAT BACK EXHAUST

COMPUTER CHIP
HYPERTECH 160* THERMO.

 

I'm sure it's doable...but you'd have to change your name from slow to smokin'V8berlinetta

 

a 403 is a small block, even though its over 400, and is 1 in shorter in height, and 1 1/2 in narrower i beleive. so the 455 would be a lot harder. i also have one of those in my garage, but its wide, heavy, and it takes a lot to make good power on a decent budjet and high enough revs. the mild 403 that i had with a th350 and 3.08s took a 2000 ws6 ta with a 6 speed. it usually got 16-19 mpg, never worse than 14. it warmed up extremely fast, it idled smooth, and it could rev very quickly because of the large bore short stroke. 3.38 stroke and 4.35 bore. in comparison, that's the same stroke as a 260 or 307 or 350 olds, with a bore bigger than a 455. it also came with 6in rods according to a computer dyno, i only had about 280hp @4750 and 385ftlbs. i had a 472 496 lift cam, true duals off the manifolds, unknown compression and porting, stock iron intake, and a quadrajet that never bogged. it doesn't sound like much, but it tore apart a flex plate as if it was paper, and fragged a strong th350

 

Hate to tell you this but a Chevy 383 stroker smallblock, or a 400 smallblock with aftermarket heads would STOMP ALL OVER a 403 Olds...It was a "smogger" engine with a 7.9:1 compression ratio and really wouldn't be worth the extra hassle to install...

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'83 Trans Am clone;
700R-4, 3.42:1 rearend, Z-28 suspension, H.O. dual snorkel air cleaner, H.O. exhaust manifolds & system, 180* 'stat, stock ECM. Awaiting 350 swap with CompCams 212/218 --.444/.444 -- 110* LSA

 

Yeah yor right, I want to hit you!!!

Don't do it!!!!!!



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Joshua Johnston
1991 Z-28


350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust,Dynomax Bullet Mufflers, T&R Motorsports custom air intake

 

I happen to be doing the swap myself. Not in my car, though. It's going to be in a 1987 Firebird LG4. I think that motor is one bad ****, well at least the one I built up.

It has a Crane Powermax cam, not really a radical cam, but has good power from 2,500 rpm to 5,500 rpm.

Here are the specs and features of my 403-

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1978 403 Oldsmobile block.
Crane Powermax 222/230 .480"/.496" cam kit.
Stock heads, ported/polished & decked.
2.072"/1.710" Manley valves.
Crane stamped-steel style 1.6 rockers.
Comp cams valvesprings.
Edelbrock Performer RPM intake.
Edelbrock Performer 750 cfm 4-barrel.
No EGR, plugged ports in manifold.
No HEI, using MSD billet distributor.
Milodon oil pan.
New oil pump.
Stock rods, pistons, and crank.
Weiand water pump.
22% Underdriven billet pullies (custom made).
Delco plugs, and wires.
Probably more to list, but that's all I can remember now.
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The reason why I changed out the whole oiling system, is because the 403 is infamous for it's oiling problems. It couldn't oil the motor very well after 5,000 rpm or so. So I changed that out immediately with better parts, including pan and pump.

It was a very fun motor to work on, it was in nice condition when I bought it for 200 bucks, then I put about 2000 bucks into it. It probably has around 300-325 horsepower I'm thinking.

I just can't wait to do something with it soon. That 87 Firebird is my friends daily driver, so we have to get his truck up and running before I start tearing it apart.

If you hate the 403, you should really read up on it. It is an interesting motor, and it would kick butt in a 3rd gen. I'll post pics when I'm done.

Furthermore, I am building a 302 for my car, just to be different, and I'm building it to 1969 specs or better. I will also post pics of that when I complete.

So many projects, so little time.

-ws6formula-

 

I'm glad someone can say that i'm not a moron for thinking about this. as for the olds v-8 oiling problems, my dad built a cheap daily driver 455 thats still sitting in my garage that he slightly opened up certain oil passages that he was told would cure old's shortcoming. outside of the lack of a decent aftermarket, olds v8's really are awesome, which is why they were made until '91, outlasting buicks, cadillacs and pontiacs traditional v-8s. if i were to go ahead with the swap, it would be impossible to keep the tires on the pavement. the one i had revved so fast and had so much torque it was ridiculous. i never took my 403 GP to the strip, but my buddies GTA is in the high 14's and my car was definitely faster, with virtually no mods. thanks ws6formula for not bashing my idea. i'd like to know how your swap goes. what are you doing for motormounts? headers/manifolds? email me @www.hipergp@aol.com

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'84 Berlinetta, LG4, 700R-4, starwars interior, no major mods yet