I have a numbers matching 68 442 convertible, I was wondering instead of putting in a 455 if rebuilding the the original 400 is it possible to get 420-450hp? I know the 455 can easily achieve this number but can a 400 get there with good street manners? Whatever I decide Ide like to run it on pump gas,again good street manners but its gotta tear it up! Thanks!

 

Have the block sonic checked to see how much of an overbore you can do safely. If you can go to 4.00 or so you can get 400 or so streetable hp with the right parts, and a little head work.

 

Eagle crank,rods and Edelbrock heads are definately on the list.

 

If you are going for aftermarket heads, why bother with a block having 1/4" smaller bore just to make that one part "original?"

 

You didn't say that initially, then I agree with RtoR.

 

I would say original blocks should be kept for cruising and restore and not hot rodded cause who knows what bad things may happen... If you want decent HP for trouncing then build a 425 or 455 and save the 400. 80% of (non Olds) people who see whats under the hood wont have a clue as to correctness anyway.

 

Thanks guys! I do have a 455 laying around Ill save the 400 to restore someday or if I sell it I have the original motor,trany and rear end. Does anyone know what Bill Travato,Mondello or Dick Miller would ask for a crate ready to run engine? (ball park) I sure its not cheap!

 

Where are you located? Shipping would be high also, and why pay for a race engine unless you plan to use it as such? There are several companies that frequent real olds power who can help you with high performance builds, and for a tractor-grade rebuild, you local shop can probably take care of you. Your plan to use Edelbrock heads suggests you do want high performance, so do your homework before choosing an engine builder.

 

You don't need Edelbrock heads or an aftermarket crank & rods to make a 450hp street engine with great torque. Talk with any of the reputable Olds engine builders over on ROP. You can achieve your goal without spending a fortune and an experienced Olds engine builder can save you money in the long run.

 

x 2

 

Mondello turn key engines start at $11,000...I wouldn't go that route.

 

Steve hopefully the 400 engine build is going good. Achieving 400 ponies from that motor is doable with the right parts and great head work or Edelbrocks. Let me know if you finished this motor, if not I can give you a few pointers.

 

L69 it's going good a little slow but good. I took the engine out put in a new roller cam,lifters and timing chain set and I'm waiting on pushrods.
I've got a new edelbrok 750 that I'm going to use so I'm keeping busy assembling and painting but I hope to get it don within the next couple of weeks. I'll let you know how it goes.

 

just replying to stay updated. im curious on the build.

 

Alright guys heres the deal! I pulled the 400 because of bad valve guides and replaced them with big valve c heads that I had rebuilt and had the egr bumps ground down in the exhaust ports. The timing chain had lots of slack so I decided to replace it along with a roller cam,roller lifters, Harland sharp roller rockers,melling oil pump and 750 edelbrock carb and performer intake. I also swapped the stock torque converter with a tci breakaway converter and installed an external trany cooler.

I already had a 3" exhaust with headers,msd ignition and an eaton posi with 3:55 gears.
I adjusted the carb and still need to properly time the engine and I have a leak in the pass side header/manifold gasket that I need to take care. I have been driving it around the neighborhood and let me tell ya it's a different car now and at some point I'll install the shift kit. It's not like some of the 455 engines that I read about on here but it's definitely a fun convertible to drive.

Ide like to thank Mark aka Cutlassefi for all the help,tips,advise throughout this project and for supplying most of the parts,I couldn't have done it without your help! Thanks Mark!

Steve...

 

You're very welcome Steve. Thank you for allowing me to be a part of your build!!

Enjoy!

 

Looking good steve. Are you going to dyno your build. I'm in the process of doing a similar build, and mark is helping me as well. He's the best! I'm looking at keeping mine looking stock. Well as stock as i can Here's heads up to all the guys who are keeping their 400s.