400 worth messing with ?
Le Mans Master
Joined: Nov 2004
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St. Jude Donor '07
I bored and built my 400 to a 405.
Nothing is different from a 350 other than the rotating assembly and maybe starter bolt pattern and most starters are built for both.
The outside is the same and all of the 350 accessories and brackets will transfer and just as many parts are available for performance since most of them interchange.
A 400 is built more for low end torque but you can get stroker kits for 400s and build a high RPM monster.
Nothing is different from a 350 other than the rotating assembly and maybe starter bolt pattern and most starters are built for both.
The outside is the same and all of the 350 accessories and brackets will transfer and just as many parts are available for performance since most of them interchange.
A 400 is built more for low end torque but you can get stroker kits for 400s and build a high RPM monster.
The longer the stroke the lower you want to go into the rpms
Team Owner
Joined: Aug 2006
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From: Columbia Missouri
Or you could drill them yourself. I did and it went fine. Oh, and if you do this don't skimp on the drill bits. You don't want them shattering while you drill. Have four or five of them on hand.
Team Owner
Joined: Jul 2001
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
On a properly built engine, you can rev a long stroke engine pretty high.. I'll have a 4 inch stroke on my 434 and the rev limter will be set to 8000 and my shift RPM will be 7600 RPM... It all depends on how well an engine is built.. More stroke also gives you a lot more torque.. Of course, the piston speed on a long stroke engine is significantly higher...
Le Mans Master
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St. Jude Donor '07
Le Mans Master
Joined: Nov 2004
Posts: 6,434
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St. Jude Donor '07
On a properly built engine, you can rev a long stroke engine pretty high.. I'll have a 4 inch stroke on my 434 and the rev limter will be set to 8000 and my shift RPM will be 7600 RPM... It all depends on how well an engine is built.. More stroke also gives you a lot more torque.. Of course, the piston speed on a long stroke engine is significantly higher...
Team Owner
Joined: Jul 2001
Posts: 182,997
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
not really.. I paid very little for them do do the clearances and on a 600+ HP engine, I'd recommend to anybody to have the machine shop measure the clearances.. The more HP you are pushing, the more critical those clearances are.. Checking the clearances with the proper tools doesn't take a lot of time..
Team Owner
Joined: Jul 2001
Posts: 182,997
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
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Le Mans Master
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St. Jude Donor '07
not really.. I paid very little for them do do the clearances and on a 600+ HP engine, I'd recommend to anybody to have the machine shop measure the clearances.. The more HP you are pushing, the more critical those clearances are.. Checking the clearances with the proper tools doesn't take a lot of time..
Le Mans Master
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St. Jude Donor '07
Team Owner
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Team Owner
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Le Mans Master
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St. Jude Donor '07
Team Owner
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From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
I don't have those kind of tools and I don't want to rely on plastigauge, so I had the machine shop do the clearances..
Yes, you got one too many zeroes..
I'm running .0030 on all main caps except for cap #1 which is .0027
The machine shop marked all the clearances on the block..
Last edited by GrandSportC3; Jun 6, 2007 at 12:01 PM.
Pro
Joined: May 2002
Posts: 518
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Amen, and mine runs no problem with a stock 71 AC/BB Rad (including extended idling in the desert with the AC on).
Be aware of the steam holes and external balancing, and if using the stock rotating assembly I'd keep the revs under about 5700 RPM.
Be aware of the steam holes and external balancing, and if using the stock rotating assembly I'd keep the revs under about 5700 RPM.
Take a look at my odd duck 406ci pulling 550HP in my sig. Parts are so available I could have sworn I saw a set of high performance 406ci pistons in the checkout at my local grocery store last night 
...and I thought we finally got rid of all the myths about overheating and few others about 400's like them being more expensive to buid..oh well here we go again. I have never heard anyone including myself that actually built a 400 based small block ever having overheating problems. THere is no cost difference to build a mild 355ci or 406ci
...and I thought we finally got rid of all the myths about overheating and few others about 400's like them being more expensive to buid..oh well here we go again. I have never heard anyone including myself that actually built a 400 based small block ever having overheating problems. THere is no cost difference to build a mild 355ci or 406ci
Thread Starter
Instructor
Joined: Sep 2006
Posts: 154
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From: Upper Darby PA
I have zero wrenching experience on a 400. luckily, I have several good machine shops and engine builders in the area. I may have them do part or all the work. I'll probably do the installation. am now fully aware of the need for the proper head gaskets and steam holes. I don't think I'll go with a stroker kit, but a $500 rad replacement seems necessary. last week a 400 conversion wouldn't have occurred to me. thanks for the education.
Instructor
Joined: Apr 2006
Posts: 114
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From: Spring Texas
I just did this with a 400 30 over with dart heads that my son gave me. I put it in my 71 vert. Drives real nice!!!
What no one has told you yet is that the Monty Carlo engine block will not have all of the threaded bolt holes that a Corvette uses. I’m assuming that you will want to hang all of the Corvette stuff on the outside of the engine. I had to drill and tap the power steering mount, the clutch linkage and the brackets that cover my spark plug wires. I missed some. The bosses should be there but no holes.
Make sure your machine shop does all of this for you.
What no one has told you yet is that the Monty Carlo engine block will not have all of the threaded bolt holes that a Corvette uses. I’m assuming that you will want to hang all of the Corvette stuff on the outside of the engine. I had to drill and tap the power steering mount, the clutch linkage and the brackets that cover my spark plug wires. I missed some. The bosses should be there but no holes.
Make sure your machine shop does all of this for you.