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Hi all, I've got an all stock 1977 Olds 442 that has the original 260/5 speed manual transmission and plan to swap a 1972 455 into it.
Has anyone done such a swap and can pass on any helpful hints? I'm wondering what parts are interchangeable between the 260 and 455 being the 455 is just a short block. Such as, flywheels seem to be either 10 or 11' with manual transmission cars...which size would be best for my application and do both share same both pattern between the two?. I've been told the factory 5 speed will self destruct with the 455 and plan to find a 4 speed for it and plan to look for a new cross member such from a company called G Force. And headers or factory manifolds?
I’m guessing any 5 speed designed to go behind a 260 won’t last long with a 455!!
Some 455 engines have no provision for the clutch pivot ball near the starter. Very few have crankshafts drilled for a pilot bearing, but any competent machinist can fix that. There are also conversion bearings, but I think they require cutting the input shaft.
Your car has a crossmember designed for a catalytic converter and single exhaust. You could use a crossmember from a 73-75 car, you may need to drill the mounting holes assuming they aren’t there. I know nothing about the 5 speed in your car, but I’m assuming it shares the same transmission mount location as either the TH350 or TH400 trans. If so, I would think drilling the holes if needed would be all the fabrication needed.
I forgot to me mention, moving the crossmember if needed will probably require some fabrication to the parking brake cables. Should be easy enough with factory replacement parts.
Headers might be a issue with the clutch linkage. Manual transmissions are not common with those cars. However, the 73-77 455 swaps that I have been involved with were able to easily use headers for the 68-72 cars. Hopefully someone more familiar with the later A bodies will have useful info
The 455 bolts in using the same mounts as are currently on the 260. The 455 was a factory option in the identical 1976 cars. The 1977 accessory brackets may be SBO only. The early 70s brackets were able to be used on both BBO and SBO. They typically had two sets of holes to fit both deck heights when needed. It depends on exactly which brackets are on your 260. Be sure to use the water pump, brackets, and pulleys as a matched set to avoid the typical pulley mismatch posts.
The 260 exhaust manifolds will bolt to the 260, but it's a really bad idea to use them. Get the W/Z manifolds used on the 442s. You'll need a 73-74 double hump trans crossmember to run dual exhaust.
The 260 bellhousing will bolt to the 455. The flywheel will bolt to the 455. You want an 11" clutch, not the 10.5". The 260 flywheel may or may not be drilled for both, but that's easy for a machine shop to do. 455 cranks won't be drilled for a pilot bearing if the engine came from the factory with an automatic. You'll need to have the crank machined, or use the aftermarket conversion pilot bushing.
The stock clutch linkage will work fine, but you'll need to be sure your 455 has the hole for the equalizer pivot drilled and tapped. The 73-76 blocks typically do not.
The stock trans behind the 260 is the T50, possibly the only five speed used behind a V8 that is weaker than a T5. It likely won't live to the end of the driveway if used behind a 455.
Hi, would the starter from the 260 also work with the 455 with the 11 inch flywheel?
It will bolt up. Whether that pencil-necked starter will reliably turn over a high compression 455 when hot is a different question. There's a reason why Olds used high torque starters on BBOs.
Hi all, I've got an all stock 1977 Olds 442 that has the original 260/5 speed manual transmission and plan to swap a 1972 455 into it.
Nice, turning the 442 into the beast it should of been.
Originally Posted by 77442
I've been told the factory 5 speed will self destruct with the 455 and plan to find a 4 speed for it
Looks like you're already veering away from the 5 speed. So this is more for future enthusiasts.
The T-50 was originally mated to a 80 HP 116 LB FT inline 4 cylinder. A subcompact that weighed 2800 LBS. Never should of been put in a midsize Olds. Especially one that weighed 3800 LBS. Its max torque compacity is 205 LB FT. So pairing with a 260 was maxing it out as is.
Unlike many a great transmission which were overengineered and therefore underrated. T-50s were under engineered and rated correctly. Thus why they are considered crap, no wiggle room with very limited application.
Originally Posted by 77442
And headers or factory manifolds?
Headers are often a headache across the board. From fitment to bottoming out and everything in between.
I am currently accumulating parts for this exact swap. We are going to do one step at a time if possible. The new 455 will be "broken in" using the T-50. Starter, distributor bell housing and flywheel will be reused and upgraded if needed. I have a factory double hump crossmember that will soon be installed I will let you know how it fits with the T+50.
The 1977 accessory brackets may be SBO only. The early 70s brackets were able to be used on both BBO and SBO. They typically had two sets of holes to fit both deck heights when needed. It depends on exactly which brackets are on your 260. Be sure to use the water pump, brackets, and pulleys as a matched set to avoid the typical pulley mismatch posts.
I am hoping this will not be an issue with my swap. I will post results when we get there. If using SBO pulleys and brackets should a SOB water pump also be used?
Yes, on the water pump but it makes a difference if it is A/C or not, different length. There are 4 lengths for Olds water pumps, using the wrong one, screws everything up. Another annoyance with the Olds belt set up, is spacers everywhere. Upon removal, take pics or write notes or diagrams. If they are not put it the right places, pulleys will sit cockeyed and not line up properly. The only thing good about the 260/5spd, is it sounds like an Olds V8, dual exhaust helps everything and the 5 spd allows a 3.23, 3.42 or 3.55 rear gear swap that would almost allow normal acceleration without over revving the weak little turd, mine sounded awful at 4000+ rpm. The factory single exhaust 260 with 2 something gearing must be exhilarating to drive🤣. Good luck
The factory single exhaust 260 with 2 something gearing must be exhilarating to drive🤣. Good luck
Original owner put over 300K miles on it 1977 442. He is excited for the upgrade and it will be a basically stock rebuild which will be close to double the HP.
When I swapped in my 455 replacing the 350, the A/C bracket was different and sourced one from a olds junkyard.
alternator bracket was fine
Power steering was fine,
Also you have to look at the pulley's. The water pump pulley could be different, as was in my case as whether I had the long neck or short necked water pump.
Yeah you will need a double hump cross member, I don't recall where mine came out of, but we had to cut some off each side so it would fit in the frame.
Make sure you have a good radiator to cool it. Get the right starter the 1st time.
Good to know about the difference of early A/C brackets, it makes sense. G body guys running the A4 compressor have to lengthen the factory 307 brackets to run a 455, since no 455's came factory with them. As far as headers go, if 20 to 30 hp is important to you, run headers. If ground clearance and over heated starters don't sound like fun, run W/Z manifolds opened up to 2.5" with Ram Air Restorations 2.5" mandrel down pipes into a good 2.5" exhaust system. It will flow way better than the factory exhaust system from 77 without a doubt.
Hi, wondering how is your 442 project coming along? I'm still in the parts gathering stage for my 442 project.
My engine is next in line at the machine shop. I have the dual hump GM cross member, 800 cfm q-jet from a 1978 Buick that will be rebuilt to match the build and converted to electric choke, performer intake, Thornton WZ exhaust manifolds,1969 C heads, two N cranks with connecting rods and an F block. I am going to meet with the machine shop soon to decide on pistons and a camshaft. I might need a set of valve covers and an oil pan for sure. Also trying to decide what color to paint it. We are getting close.
The idle mixture will be way too lean on a 78 carb on even a stock 455. Those passages have to be enlarged, hopefully your guy knows the Qjet. Then by all means, tune it with a wideband. If he gets it close on the tune, adjusting the APT might get the fuel curve spot on without removing jets or rods.
IMO as far as the carb goes...You want it done right? You want to optimize the carb? Send it out to Cliff. (Rug-gles as in an area rug-gills is how he pronounces it).
Most are unaware of the tuning secrets within a QJ to extract the most.
After Cliff has his way then do the wideband tune with Air/Fuel and ignition.
Note:
Make sure you call him AND put your phone number in the box attached to the carb preferably with a large tag.
He will call you to discuss the particulars. He'd much rather talk to you versus read a text or email.
The idle mixture will be way too lean on a 78 carb on even a stock 455. Those passages have to be enlarged, hopefully your guy knows the Qjet. Then by all means, tune it with a wideband. If he gets it close on the tune, adjusting the APT might get the fuel curve spot on without removing jets or rods.
Thanks for that information. Rod has been doing carbs for decades. Everything from daily drivers to drag cars and circle track. I will discuss the build with him to make sure he will be successful. I might consider ordering parts from Cliff or send him the carb but 12 weeks is a long wait. There is a local Chevelle guy who is great at getting the final set up done so it will probably end up with him.
She looks really good. That blue and black combination is sharp. Mine had the Red and white stripe combination with a white interior that'll show every stain whether big or small.
In your later post you were going to use the same flywheel but did you use a 10.5 clutch or move up to a 11.00 clutch? I was also considering the same flywheel bud wasn't sure if a bigger clutch would fit in replacing the older one.
Was also going with a G Force cross member but I'm dropping a brick at the price. Heard about using a 70-73 cross member but wasn't sure if the t-50 would also fit.
One more question, did you get your crankshaft drilled for the pilot bearing?
I've been looking at pilot bearings and totally confused at the different ones. Should I get the one for the 77 260 or the earlier 455 block? about to give up and just get the modified pilot bearing everyone else is talking about and grind down the nose of the t-50 shaft.
Which holes? New engine is still on the stand. I have a GM double hump cross member. I was going to check fitment before pulling the transmission but forgot to do it. The crank I am using is drilled for the small pilot bearing, maybe because it came out of a L9EO engine? Joe have you seen this before? I bought a good used flywheel to use when balancing the engine. Both flywheels are drilled for both clutches. I am thinking about using the same clutch for two reasons. It may help the T50 survive and if the transmission gets replaced it will be with a Tremec and I do not know if a stock clutch would work with it.
Sorry, I meant the bolt hoes for the cross member. The original 77 cross member is not straight across the frames but one end is further up on the frame due to the catalytic converter. .The original earlier cross members are straight across frame to frame.
Sorry, I meant the bolt hoes for the cross member. The original 77 cross member is not straight across the frames but one end is further up on the frame due to the catalytic converter. .The original earlier cross members are straight across frame to frame.
The straight crossmember from 73-74 will fit the 77 frame rails, but you may have to drill holes to match.
I just checked, this car has four holes on both sides. It is hard to tell without the transmission in if they will work. It also looks like I will need a longer intermediate parking brake cable and/or a different "hook" to the cross member.
I got the transmission and cross member in yesterday. It is a tight fit. I had to put the mount on the cross member and then slide it under the trans. I need to drill one new hole on both sides of the car.
The stock trans behind the 260 is the T50, possibly the only five speed used behind a V8 that is weaker than a T5. It likely won't live to the end of the driveway if used behind a 455.
The T50 in this project just pass 800 miles and still going.
Apparently the 455 is putting out around 205 ft/lbs😉. That transmission is tiny. See, miracles happen every day or at least every time he drives it. The Admin on the G body site had one behind an Olds 403 die quickly. Tell him to buy a lottery ticket.
September 24th, 2020, 08:56 AM
455 swap into 77 442
