CP888

I have searched through the forms and a few other sites and there are a few questions that I have not found definitive answers too. Hopefully someone that has experience with this swap can answer a few questions I have. I want to make sure I have everything lined up for the swap in spring.

1. I know my 350 mounts will work with the 455 but I have also heard the motor will sit higher. My motor will have a procomp intake. Will I have hood clearance issues with using the aftermarket intake?

2. Will the 455 headers have more of a fitment issue because of how the the motor sits with the 350 mounts?

3. I have the adapter plate and shiftworks dualgate adapter for the 700r4. I have read that the crossmember will have to be moved back and the driveshaft will have to be shortened. Will the shortened stock driveshaft be strong enough? I am waiting on dyno sheets but the motor is supposed to be 500hp and around 600ft lbs of torque. I have also heard that the parking brake lines will need to be changed; will th400 lines work with this setup? Also what transmission mounts should be used? Is there anything else I will need for this transmission swap?

4. Will stock fuel line size be okay?

Thanks,

Carter

Fun71

joe_padavano

One more time...

https://classicoldsmobile.com/forums...tion-list.html

cutlassefi

You need 3/8” fuel line minimum.
Can you tell us what else is in the engine? If you're interested I can probably tell you what it’ll be making even before you get the dyno sheets.

olds 307 and 403

Good luck on a 700R4 holding up to 600 ft/lbs. The 4L80E looks awful attractive at that torque level, a few minor mods compared to a complete 700R4 with nothing stock inside.

joe_padavano

Especially when you consider that a 4L80E is really just a TH400 with an extra OD gear set an clutch pack right behind the front pump.

CP888

Thank you for the info on the intake clearance and headers. I think I have 3/8th lines so I shoul;d be good. I can throw the parts list on here when I scan it. I saw the thread on motor mounts but I am unsure if there are separate mount numbers for the transmission or if it just sits on the cross member. I don't have any experience with this. The business building the motor is giving me a 2 year warranty on the transmission so we will see if it holds up. I looked at the 4l80e before but I didn't want to deal with the computer and wiring. If the 700r4 doesn't hold up I may eventually go that way.

cutlassefi

You never told us what's in the engine.

VinMichael

camdon454

I have the same combination in my 70 Cutlass S with Procomp and using the small block motor mounts. The hood is still off right now and not in the same shop but it looks iffy. I'm going to try a low 2" air cleaner with the filter on top as well to get the airflow required. I had no idea the small block mounts would leave it an inch higher, should pay more attention to these threads. That extra inch could make all the difference. ..."That's what she said!" Lol

camdon454

Oh and I got my Heddman headers to fit but had to remove my driver side motor mount to do so. Now my column shifter linkage doesn't seem to be even close. Killing me.....

joe_padavano

You should actually pay attention to THIS THREAD. Small block mounts DO NOT "leave it an inch higher". The 2261 mounts and matching frame pads put the crank centerline of ANY 1964-1990 Olds motor in EXACTLY the same place as do the 2328 mounts and matching frame pads. With either set of motor and frame mounts, you cannot lower the motor any more without taking a cutting torch to the crossmember.

The BBO is about an inch taller than an SBO (which is WHY it's called a big block).

CP888

I can deal with finding a shorter air cleaner. Good to know the big block mounts do not make a height difference. I have a console shift so I won't have the column shift problem with the headers. I don't see a point in listing everything in the motor since I trust the shop and he has built and dynoed many 455's identical to the one he is building for me. I think I will move my transmission questions to the transmission forum since that is now my main concern. Thanks.

Fun71

Camshaft, pistons used, final compression ratio, any head head work performed. What else is there to list that makes this so difficult?

CP888

I guess what I meant is that it would not help answer my questions providing the build when I trust the builder. The list he sent me is a few pages long but it includes srp forged pistons, port and polish stage 3 for head work. I can upload the quote when I figure out how to take my payment info off.

joe_padavano

There's always this method...

droptopron

If the Russians get this guy's plate #, who knows what they'd do with it?

joe_padavano

I always have to ask these clowns if they have to have someone run behind the car with their thumb out when they drive on the street...

Fun71

Prolly don't need a list several pages long. I mean, things such as installation of cam bearings and hot tanking a block aren't going to be meaningful in determining the engine's power level.

VinMichael

CP888

I posted this thread to see what I need for the swap. I appreciate the vote of confidence though.

cjsdad

I think the point here is that we are all rabid gear heads and love to hear about proven engine combos. I haven't built an Olds engine yet, only repaired them so learning what works is great. Bench racing an engine is always a lot of fun and no disrespect is intended towards you or your engine builder. Just like seeing pictures of car builds we like to see engine build component lists. Cutlassefi is an engine builder so he can most likely verify your build from the parts list. Not to bash your builder, but maybe make a recommendation or two that can improve the output.

danktx

I am working on the same combination for my car (1967 cutlass convertible). I already have a 700R4 behind the 350 that's in the car now. The trans cross member does need to move back. That does require an adjustment to the emergency brake cables but the rears don't need to be replaced. I bought a short intermediate cable then extended the threaded rod using a coupling nut and some all-thread and made a new hooked rod for the passenger side. I did this so I would not have to replace the front cable. Since my car is a convertible and has a boxed frame I had to make frame brackets for the inside of the frame rails so I could mount the trans cross member in its new location. With regard to your drive shaft strength, the guy at the driveshaft shop sold me a new drive shaft since mine was a two piece with a rubber insulator and would not shorten it, you may need to replace yours if it is like mine.

CP888

Thanks danktx. I think I have everything I need now for the swap. Some of the parts/specs in the build include:
- 268/276 lunnati camshaft
- port and polish stage 3 C heads
- resized rods
-bored to 461
- holley 80528-2 carb
- srp 206072 forged pistons

There is a lot more machine work and parts on the list but those are the main parts. It was just dynoed at 520hp and 566ftlbs. The 700r4 is built up somewhat so hopefully it holds up. Ill find out in a couple months when I get it all installed.

csouth

The crossmember will need to be moved based on transmissions having different mount locations. The driveshaft will need shortened depending on what TH350 you have. Best thing to do is measure since most of these cars have been swapped something at some time or another.

olds 307 and 403

Who built your motor up there in Saskatoon? I am in Melville, Saskatchewan, 4 hours south. Did you upgrade your radiator?

CP888

I will be doing some measurements for the driveshaft once I get the car out of storage in a month or so. The motor was done in British Columbia with oldsperformanceengines. I upgraded to a champion aluminium radiator with electric fans a couple years back so I will be using it with the new motor.