Author Topic: 455 olds swap  (Read 704 times)

mikebooms

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455 olds swap
« on: May 01, 2018, 06:08:06 PM »
My 403 has too many issues to fix as I stated in another post. I have an olds 455 complete still in a toronado. I've seen conflicting statements on the swap. A/c box , brake booster, accessories brackets, etc. has anyone actually done the swap, and if so can it go with minimal issues while retaining ac , shaker etc. post pictures if u can.  Thanks

welderguy1

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Re: 455 olds swap
« Reply #1 on: May 07, 2018, 07:41:41 PM »
It just drops in. You are actually ahead with toronado engine. Intake is lower. All brackets work except alternator stamped piece. Had to add on and redrill new hole for bolt to water pump. They make notched valve covers for Ac. Basically a drop in.

kingwil

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Re: 455 olds swap
« Reply #2 on: July 16, 2018, 03:27:24 PM »
Mikebooms, hope your swap from a SBO 403 to a BBO 455 is going well.  Any clearance issues on the passenger side by the Heater/Evaporator Core Box?  It looks tight on the passenger side with an Olds 403 and a Pontiac 400 or 455.  What type of clearance (in inches) do you have between the Heater/Evaporator Core, and the heads and valve covers on the Olds 455?  Same question for welderguy1.  What kind of space (in inches or fractions of an inch) is between the Olds 455 Engine and the Heater/Evaporator Core on your TA?  Can you elaborate on your mention of the Notched Valve Covers?  Is this something you can buy?  You also mention the brackets for the alternator might give some trouble.  So, you can't take the accessories (water pump, power steering pump, AC Compressor, and Alternator) and just bolt up?  You need to fabricate something for the alternator?  Or get a bracket for a 455?  Next question, can you use the belts for the accessories from the 403?  The reason I am asking is that I have access to a BBO (Big Block Olds) 455, but just the engine block and no accessories.

For both Mikebooms and wlederguy1, are you using Headers with your Olds 455 or are you using performance exhaust manifolds (like W & Z) from a 70-72 455 or other Exhaust Manifolds?  How are these fitting, especially on the passenger side with that old nemesis, the heater/evaporator core box for AC?  If using headers, are they specific for a Firebird TA or did you have to get something custom made?  I have Headers on my 403, but doubt I could bolt them up to a 455 due to the Olds 455 heads sitting 1.295" higher than a 403, plus I don't know what other clearance issues might arise.  So, what did you do from an Exhaust Manifold or Header standpoint for your Olds 455?     
79 Nocturne Blue 403 Firebird TA
72 Viking Blue 455 Cutlass Convertible

welderguy1

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Re: 455 olds swap
« Reply #3 on: July 31, 2018, 07:31:14 PM »
My car was originally a non Ac so I can’t help with those clearance issues. There are oem Oldsmobile valve covers that have clearance notches for the brake booster and heater box. Google them. All the 403 Firebird brackets work except for the stamped alternator bracket. I had to move the hole which mounts to water pump. Just added some plate and drilled a new hole. I used w z manifolds with pypes 2 1/2 exhaust. Lots of clearance. I’m a welder so I cut down the shaker base and used an airaid conical filter the sits up inside the shaker. Works great.

kingwil

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Re: 455 olds swap
« Reply #4 on: August 14, 2018, 04:09:17 PM »
I found some Notched Valve Covers in the Fusick Catalog for Cutlass/442 restoration, and it looks like the notches are in the right place for some extra clearance around the heater/evaporator box, plus around the larger Brake Booster for the 4-wheel disc brakes that came with the WS6 Handling Package on a 79 TA.

You mentioned W and Z Exhaust Manifolds.  I have those Performance Manifolds on my 72 Cutlass/442 Convertible.  Are you suggesting I find another set of W & Z Exhaust Manifolds and not pursue Headers with a Big Block 455 Olds in a 79 TA? 

I saw a 1979 10th Anniversary TA with big Block Olds 455 bored and stroked to 496ci at the Tri-Power Nationals at Norwalk, Ohio a week go, but the car did not have the Heater/Evaporator Core on the passenger side, so no clearance issues when the owner decided to swap out the Small-Block Olds 403 for a 496-cube Big Block Olds.  Car also had aftermarket Wildwood brakes and much smaller aftermarket brake booster and master cylinder.     
79 Nocturne Blue 403 Firebird TA
72 Viking Blue 455 Cutlass Convertible

Re: 455 olds swap
« Reply #4 on: August 14, 2018, 04:09:17 PM »

olds403

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Re: 455 olds swapsta
« Reply #5 on: August 14, 2018, 09:08:23 PM »
Install a hydroboost and will have plenty of room on drivers side. 

welderguy1

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Re: 455 olds swap
« Reply #6 on: August 24, 2018, 07:10:49 PM »
I think you would have a hard time with headers. Not saying it can’t be done but I wanted to have no problems with the backdrive for the shifter and to be able to get starter out if I had too. I used the notched valve covers with stock booster because I don’t think they would come off without them.

Re: 455 olds swap
« Reply #6 on: August 24, 2018, 07:10:49 PM »
You can help support TAC!