When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hello Oldsmonuts, I'm in need of some suggestions, ideas, just bought my wife, {wink, wink} a 79 T/A, 403, beautiful car, until you step on it. I believe it to be original bone stock 180 hp boat anchor. I'm not looking to go drag racing, just want to wake it up a little, if it's possible. Thanks in advance, Jim.
The 403 is a big cube motor that has great potential but is emissions choked. Research exhaust improvements, distributor recurving and camshaft. Getting more air in and out is the name of the game. Maybe later a better cylinder head and higher compression. But for now good tuning will help a lot. The original Quadrajet on your car is one of the best ever made, get Cliff Ruggles Quadrajet book if you like doing hands on stuff. Good luck, post some pics if you can.
Thank you, I will post as soon as I get a chance, I am in north east Pa, now that it has finally stopped snowing, it has been raining since we brought it home. It has not been out of the garage since i parked it in there.
The engine is so nicely painted , I almost don't want to touch it!
As far as exhaust, It is sporting the stock split system.
Yes, 64 to 72 330 or 350 heads with 2" or 2.07" intake valves and 1.625" exhaust valves. That will bump you close to 9 to 1. Add a cam and dual exhaust.
If you choose to go this route,(highly recommended by the way) I can do several different 330-350 heads. Probably the best bolt on you can do to increase the power of these engines
thank you.
it is a y84 special edition, ws6 optioned car, (handling package, 4 wheel discs)
aside from being not as fast as it looks,
We are happy with it, so far.
as said it s bone stock, down to the exhaust system .
We hope to enjoy it this summer as it is, and I will begin researching some engine mods , and do them over the winter., but the exhaust may get done soon.
Very nice car. I had a very similar car years ago. Some of the things I did to help it drastically in the performance part was: bought another hood shaker that looked as good and opened it up to make it functional, installed a K&N air cleaner and air cleaner top, making it full ram air, drastically tuned it, changed the jetting and carb function, (I had a friend do this so can't say what all was done) I used another correct carb so kept all the original stuff so it was all bolt on, I have another one of these carbs if you go that route, I also had full true dual exhaust done to it as well. where I live we can get away with this as we do not have inspections, These things drastically improved the performance over the stock car. But, in time changed the heads which was the most significant improvement. The stock 403 4A heads are like an open chamber and smaller valves and it just did so much better with the earlier 4 (off a 67 330) heads, larger valves and smaller combustion chambers which drastically improved the compression ratio. I never changed the rear end gears but I do know many of the Trans Am's had 2:41 gears which are very restrictive to lower end performance.
Thanks Larry, and everyine else for all the replies.
I have a 75 & a 74 350 , I assume those heads would be useless.
while I consider myself capable of all these suggestions, I am unfamiliar with the details and specifics on what parts to use, so thanks again, I think I will start with exhaust sytem, and continue onward from there.
Yes those heads would not be so great for this. 65-70 is what I would stick with. As they are the larger valves and smaller combustion chambers. I would of course completely rebuild them if I was you so you are starting fresh. Almost all of those are the same basic head just different cast numbers and letters. You will have to enlarge the head bolt holes if I remember correctly as the 403 used a larger head bolt. but very easily done. Greg Rolin at Supercarsunlimited.com can help with a cam and other needed items and his knowledge is incredible and he is one of the nicest guys you will ever know in this industry.
enjoy that great car. One of the best Olds applications ever. I keep looking for one to put a really nice 330 I have in. They were 320 horsepower stock and are a bolt in.
Thanks for all the info. I will be on the lookout for a parts car of this description.
I am in no hurry, as the car is 100% operational as is, but after a car show or two , that can change. Hell, i can't even take it out of th garage till mid nextweek based on weather reports. I am interested on the distributor mods, and what to bump the timing up to, that I may tinker with.
I put a call in to a local shop to get a price on exhaust, have not heard back.
Even my wife is getting antsy to drive it!
I do want to keep stock engine, as it is correct for the car.
Hello genltlemen came across the following heads 1964 #1 330 heads high compression, from 64' 442 casting # 381918, with #2 below it.
$295 obo., any thoughts or advice..
Also, the screming olds chicken came to a screeching halt Sunday on her maiden voyage, overheating, then refusing to turn over.
Battery and starter good, I pulled and checked them, and then had them checked at advance to make sure. Car will roll in drive, I am hoping it is a negstive cable ground issue due to fresh engine paint.
Not cool
Jim, gorgeous T/A! Sorry for the bad luck. Although battery terminal ends may be clean, the wire inside the sleeve may be corroded. If they're the original cables, replace them. Cheap insurance. Resistance increases with heat. Hot internally corroded cables=no start. Good luck.
Hello genltlemen came across the following heads 1964 #1 330 heads high compression, from 64' 442 casting # 381918, with #2 below it.
l[/i]
IMO stay from the #1 heads. they have the non existent rocker systems and will not have the larger valves. The bolt holes will have to be drilled out to 1/2 inch also. I would (if you insist on 330 heads) go with some #4 or some #5-#7 350 heads.
I am a fan of the 403 - I have a 450HP+ (haven't been back to the dyno since cam swap) build in my Supreme.
The main problems from the factory:
The heads are terribly restrictive
The compression is really low
The cam is lazy
Going to small block heads solves the first two in one fell swoop. There are typical modifications to be made to Olds heads. Just post a parts wanted ad here and I bet you'll get plenty of offers for cores.
The Olds valvetrain isn't (easily) adjustable, so pick your poison there. The Comp roller tip set is the cheap way out, but throw away the pinch nuts and the pushrods that come with the kit.
Bill Trovato wrote a good book on building performance Olds engines - pick that up. The old Mondello Tech Reference book can be useful as well, but take everything with a grain of salt in that one. And, sadly, never buy any parts from Mondello Performance.
IMO stay from the #1 heads. they have the non existent rocker systems and will not have the larger valves. The bolt holes will have to be drilled out to 1/2 inch also. I would (if you insist on 330 heads) go with some #4 or some #5-#7 350 heads.
With the stock pistons in it - head swap to early 350 heads or 330 1967 heads. I have used 4’s, 5’s and 6’s. CutlassEfi is doing a set of 5’s for me right now. Talk to Mark.
It will wake up your 403, but will need to consider the expectations as you need more fuel, carb work, exhaust work, cam, valve train updates, and ignition (dizzy) work to make it all work. I’ve done this twice.
We own 3 1979 Trans am’s all with 403’s. Two of them are getting motors this year. Mark supplied all the parts and heads. Blocks we did here, but one short block has turned into a fiasco.
If it was me, pull the orginal 403, build another. That is what we are doing for our 10th anniversary trans am.
As for your overheating, the front oft these cars dont get much air. If the radiatior is not a 4core that is something to think about. Also, check fan clutch. Use the HD one if yours is bad. Also, stock starter not very good. We use McRobb starters....always turn over.
Thanks for your response, I will be looking at it the next few days. In the mean time, if this motor is fried, I will be throwing a mildly worked 350 that was built for my long suffering delta 88 conv.
I really think this motor is seized.
I could not find any information on the web about Tiger Paw GT reproduction tires, and even searching for Tiger Paw GT didn't get any hits, I saw only GTS and GTZ. I suspect your tires are much older than you think.
Put a breaker bar on the motor, you need a 1 1/8" socket. If it doesn't turn over by hand, it is toast. I liked the torque the 403's torque but like the 455, it tends to run hot. I am considering putting a 9.6 to 403 in my Cutlass but it means a new radiator and even then it will probably run hotter. I have a whole .039" oversize stroker combo for a 403, I just have reservations about cost vs end result, running hot and bottom end failure being my main concern. With Cutlassefi's 420+ ci 350 stroker combos, there is no need to run the 403.
Yes, i did that Sunday after it rolled off AAA flatbed, she did not budge. I want to keep it a #"s correct car, so the 403 will be rescued IF POSSIBLE. I will be installing a 350 Olds while this gets sorted out. The 350 has been on a stand for years, but it turned easily with plugs in, with a breaker bar. I was looking for the spec sheet on the engine , cant find it, of course.
Now i am learning there are little to no header options for Olds powered Birds.
i need to know how to get around that.
Yes, i did that Sunday after it rolled off AAA flatbed, she did not budge. I want to keep it a #"s correct car, so the 403 will be rescued IF POSSIBLE. I will be installing a 350 Olds while this gets sorted out. The 350 has been on a stand for years, but it turned easily with plugs in, with a breaker bar. I was looking for the spec sheet on the engine , cant find it, of course.
Now i am learning there are little to no header options for Olds powered Birds.
i need to know how to get around that.
Yes there are. Any SBO header that fits a Cutlass 68-77 should fit that car just fine.
25 years ago when I worked for a little company called Super Shops (closed in the mid to late 90's) I saw in the hooker catalog that the same headers listed for a 350 Cutlass also fit a 403 T/A.
I had a guy swapping in an Olds 455 and nobody listed headers for that application. I suggested the Cutlass 455 headers because the 350 ones fit the 403 and he said to order them up and if there were any issues he'd just "make them fit".
After he installed them he came back and told me that they fit like they were made for the car.
I passed the information up the line and they ended up in the engine swap section of the next hooker catalog.
Thanks to you also.
I have found several options since my last post. I noticed exactly what your stating as I searched headers on evilbay.
I guess it's time to spend more $$$$$
PM me if you are interested in my 403 stroker assembly, off set ground Olds 330 forged crank by Ohio crank, Scat 6" long with 2" journals with used 4.390" custom 550 gram Venolia custom forged pistons, rings and decent used rod bearings. I paid $600 shipped for crank, fresh machined and $400 shipped for the used pistons and rods. I will sell for much less, have another 330 crank balanced for similar stock weight pistons to revive my 403. Your block would need a .039" overbore, might need that to clean up, if seized and the whole assembly balanced. With stock heads, it would give 8.6 to 1 compression with 0 deck. Mill the heads .030" or Edelbrock/Procomp heads would put you at 9 to 1. Good luck.
I will keep it in mind , thanks, but honestly I am not keen on any used internal parts.
I need to get this thing out and dissassembled, & evaluated, and I may be working O/T this wkend, so another delay. The shop that rebuilt my 350 is a stone's throw from my house, went to see the owner this morning, but he left for holiday weekend. he has built a lot of engines, race, tractor pulls, hot rods etc.
I am definitely putting my 350 in just to be able to have my, wife, (and I) cruise it a little.
first things I'm buying is a radiator & a fan clutch.
Sure, your call. Only looking for maybe $250 Canadian($194) in the end plus shipping, would depend on shipping obviously. I just don't trust the flimsy 403 block, extra cost for a girdle and the ported heads I have are milled to much for useable compression with the stroker combo.
Sure, your call. Only looking for maybe $250 Canadian($194) in the end plus shipping, would depend on shipping obviously. I just don't trust the flimsy 403 block, extra cost for a girdle and the ported heads I have are milled to much for useable compression with the stroker combo.
Thanks again, I am hoping to know the fate of the 403 soon, but, like everyone else, time is my enemy. I bought this car because I did not expect to be in this predicament with it so quickly.
This puts my 75 Delta on the back, back burner, and my 73 Caddy needs attention, and I am currently buying tires as we speak for a 280,000+ miles 2012 mazda 3, which i believe would have taken the TA in a drag race!
I had endless heating issues with my 403. Get a big 2 core aluminum rad, good shroud, heavy duty clutch and 7 blade fan. Do not use a Mr Gasket high flow thermostat, under drive pulleys and a single core or 3 core aluminum rad. Also factory electric fans, I used Dodge Stratus fans on my 88, cooled quite adequately but controllers, thermal switches and relays are anything but reliable. The Robert Shaw high flow thermostat is much better. The Mr Gasket thermostat flowed at idle and then closed or close to it at highway speed. Also make sure all air dams are in place.
I am a fan of the 403 - I have a 450HP+ (haven't been back to the dyno since cam swap) build in my Supreme.
The main problems from the factory:
The heads are terribly restrictive
The compression is really low
The cam is lazy
Going to small block heads solves the first two in one fell swoop. There are typical modifications to be made to Olds heads. Just post a parts wanted ad here and I bet you'll get plenty of offers for cores.
The Olds valvetrain isn't (easily) adjustable, so pick your poison there. The Comp roller tip set is the cheap way out, but throw away the pinch nuts and the pushrods that come with the kit.
Bill Trovato wrote a good book on building performance Olds engines - pick that up. The old Mondello Tech Reference book can be useful as well, but take everything with a grain of salt in that one. And, sadly, never buy any parts from Mondello Performance.
Hi Oddball, you have a part #, brand for fan clutch & radiator, they will likely be first parts i buy
I had endless heating issues with my 403. Get a big 2 core aluminum rad, good shroud, heavy duty clutch and 7 blade fan. Do not use a Mr Gasket high flow thermostat, under drive pulleys and a single core or 3 core aluminum rad. Also factory electric fans, I used Dodge Stratus fans on my 88, cooled quite adequately but controllers, thermal switches and relays are anything but reliable. The Robert Shaw high flow thermostat is much better. The Mr Gasket thermostat flowed at idle and then closed or close to it at highway speed. Also make sure all air dams are in place.
do you know part #'s for fan clutch, radiator?
I think I should buy that first.
May 15th, 2018, 08:46 PM
