403 pistons ???

[Cruiser]

I am rebuilding my t/a 403 The bore is standard (Low miles) If I have to I will bore it for larger pistons if this is my only option. This will be a warmed up street engine.
Aries sells pistons ,but my engine builder dosen't like them ,he has had problems with the skirt area.

I want to use an off the shelf piston if possible.The stock pistons are very heavy.
Any ideas???
Thank's Mark Ball / Cruiser

[79TA455STROKED]

I have heard nothing but good things about the aries pistons.I believe kb has pistons for the 403 now as well.Go to www.realoldspower.com those guys can point you in the rite direction.

[Cruiser]

T/A Thank you for the info .This will be my first olds build up I usually go with the 455 pontiac swap. But I want to be able to attend both olds and pontiac meets this summer.
I have always liked both brands, Pontiacs and oldsmobiles (Pontiacs are still my favorite).
With this car (85 Parisianne body) it came with a 307 olds so a 403 swap will let me keep all of my brackets and mounts intact. Plus if built right(Main Girdle) and not overreving it it should live,and still make a lot more torque than the 307.
Thank's Mark Ball / Cruiser

[79TA455STROKED]

No prob.I had the 403 in my 79 ta before i started restoring the car.im going with a pontiac 455 now but the 403 is a great motor.I had mine built before all these new parts that you can get now came out.You can really do alot with the 403 now.The guys on that web site really know there stuff and if they havent already,they prob will tell you to talk to terry at FCR PERF.He is the man when it comes to the 403 and i believe he has a 400hp package now that you can get or use as a guideline for your build.I dont know how far you want to go but 400hp in the 403 is pretty easy to make now and you can go alot further too.Good luck and if you need any help,just ask.I prob still remember alot about the 403 if i jiggle my brain a little.

[engineer]

TRW made forged pistons for olds which are still available at local auto store.

[machine shop tom]

Don't spend too much money until you have your 403 heads checked for cracks. I haven't seen any in YEARS that weren't cracked badly.


tom

[olds]

Fyi...the speedpro / trw forged are gone. Discontinued. That leaves cast junk pistons or the KB 6cc pistons. There is always custom.

[67copperbird]

Cruiser,
Check with Mondello's or Dick Miller racing. Mondello's use to sell a book on Olds performance upgrades. Many of the upgrades weren't noticable on the outside of the engine. personally I would see if you can score a "N" crank or a steel "330" crank and use the 330 flywheel. I also wouldn't be afraid to use Arias pistons. They have been around forever, even for Olds motors. As far as heads go find you a set of "7" or "7a" heads. These were used in the early 70's on two barrel 350's. they have a smaller combustion chamber. All you will have to do is have your machine shop open up the bolt holes for the heads. You can alos have them install W-31 size valves. Be sure to have them do some work around the intake valves so they are shrouded up. Anyway I would get his book, it cost about $25.00, but is full of good information.

[Cruiser]

Thank's for the information I am going to check on the heads tonight.I think they are ok they came out of my dad's with very low miles.They were hot tanked & magnafluxed.I havn't been able to locate used olds parts here locally ,all of the junkyards locally have crushed mostly all cars from mid 80's down.The book sound's like a good idea.

Thank You Mark Ball/Cruiser

[67copperbird]

Cruiser,
I don't know if you shop there or not, but there is alot of good Olds stuff on ebay. I wish I had access to this when I was in to them. There is always intakes, and good heads (C castings, and w-31 stuff) on there all the time. I was checking last night there was even an all aluminum olds prototype small block. Check it out I am sure you will find some stuff.

[Cruiser]

Well I just got the heads back from the machine shop .He cleaned them and magged them and said that they were the best set of castings he has seen come in for a long time. I am going to drop off the short block for inspection tomorrow or Monday.I am probably going to go with the Arias pistons.
Stainless valves.
Any good recomendations for a cam & Kit?
I will be studding the bottom end and using the J & S machine main girdle it looks like a quality piece,this should help with the windowed mains.
I am going to recondition the rods and add ARP bolts.

Description:Car weight 3100 lbs., 3:42 posi, Pump gas friendly compression,700R-4 tranny,Performer RPM intake,Headers,HEI,Quadrajet,
I will be starting on porting the heads next week or so.This is gong to be a street cruiser with AC.
Thanks Mark Ball /Cruiser

[olds]

Are you using stock heads ? If so, I would use the KB pistons. You can get them on Ebay. See KB's website for the details. You use Ford 460 rings with the KB's.

While you are talking to Jim and J&S get his torque plates for when you bore the motor. Also, the KB's have unique oversize requirments. They are .024 and .039. Just make sure your machinist is aware.

My 403 has an Ultradyne cam in it which was ordered from FCRperformance. I have ran Comp Cams before in two other 403's The UD cam pulls from 2500 all the way to 5000. Use a Rollmaster timing chain.

Valves..the stock ones will be fine. Just clean up the exhaust ports. Grind out the EGR bump. J&S has some pics up of ported 403 heads. Just take look and go easy. I did the exhaust side on my old set. Its about all they need

olds

[Cruiser]

Thank's for the help Tom,Ben,Olds, the machine shop owner who does my engines always asks me what do I have now when he sees me coming.
I like having something a little different ,He has built several 455 ponchos as well as olds aluminum 215 for my vega,I have a 455 pontiac as well as a coulpe 400s stored.
However this 403 has sentimental value because it is out of my dads 79 trans am, I have hung onto it for over 20 years looking for the right project .
It will be going in my superstepside kit car ( www.superstepside.com ) the chassis origionally had an olds 307 so the 403 should make an easy swap. By swaping the body I have lowered the weight of the vehicle around 600-700 lbs.so it weighs 3100-3200 lbs.
I am installing a 3:42 gear as well as a posi unit. So with the lighter body as well as the warmed up 403 it should make a nice combination for summer cruising.
Also since the donar car was was origionally a Pontiac Parisianne with an olds motor I will be able to attend olds and pontiac events as well as kit car events with this car.
I only have three more years and till retirement, then I will have a lot of time to play with the cars.
Thank's Mark Ball / Cruiser