[BRUTAL64]

Originally Posted by enkeivette

What's the stock rod length on a 400sb? Is it a problem from the factory?

DurangoBoy, don't get pissed with the our low hp estimates. I know I prob would have in your situation, just realize that if you want 400+ wheel hp, and that's your goal (not a fun torquey DD) than you might want to consider putting your project on hold till cash permits some more aggressive parts. Because come dyno day, I hate to say it, but you'll likely be disappointed. Either step it up or install some juice along with your new powerplant. But for a DD, I think your setup is pushing the comfort zone as it is.

When HotRod tests these cookbook engines, they test them at the crank, with no accessories, with gigantic open headers. And after hours and days and weeks of tuning, they make some pretty impressive numbers. Numbers that you will never see.

Stock 400 rod 5.5 inches. Pluses- quick low end torque.
Negatives -weaker than 5.7, not good after 4,500 and heavy piston side loading.

[BRUTAL64]

Originally Posted by enkeivette

I was talking about DBs motor, don't really know anything about the H&C in your motor.

And Glenn, that's what I use the program for, checking changes. Lift, boost, header size, etc.

Not a problem. Just clearing the air on some things.
I know everythng you do is well thought out. If everyone approched engine building the way you do, I'd have nothing to write about. In a lot of ways you remind me of the way I was at your age.


Oh, meant that in a GOOD way.

[enkeivette]

5.5" ?! No way, that's weak! Step up to the 6" rods DB, I take it back. Or score some junkyard 5.7" rods... if that will work?

[BRUTAL64]

Originally Posted by enkeivette

5.5" ?! No way, that's weak! Step up to the 6" rods DB, I take it back. Or score some junkyard 5.7" rods... if that will work?

Yea, the stock5.7 rod will work, but you need to clearence the pan rails and two rod bolts for cam clearerce. I did it by hand in 88. Not real hard.


Just easier to get the Scat rods (stroker rod) at 285.00 buxs and be done with it.

[enkeivette]

If cash is tight DB drive down to Pick Your Part and spend a few hours under a Chevy truck. A few hours and $30? later... you'll have a better motor.

Don't know if these will work, you need to know the specs, but check it out. 6" rods for $80. http://cgi.ebay.com/ebaymotors/6-I-B...4506.m20.l1116

5.7 Rods, $10 for the set!!!
http://cgi.ebay.com/ebaymotors/Set-o...4506.m20.l1116

[BRUTAL64]

Originally Posted by enkeivette

If cash is tight DB drive down to Pick Your Part and spend a few hours under a Chevy truck. A few hours and $30? later... you'll have a better motor.

Don't know if these will work, you need to know the specs, but check it out. 6" rods for $80. http://cgi.ebay.com/ebaymotors/6-I-B...4506.m20.l1116

5.7 Rods, $10 for the set!!!
http://cgi.ebay.com/ebaymotors/Set-o...4506.m20.l1116

If you do it that way, this is what you look for. Late sixies thru late 70s "X", "B" or "O" rod. Stay away from the Mexican "X" rod with the large flat on the side bolt boss. Some 305s and 307s used the "B" rod.


FYI; The most common rod used for the PINK rod is the "B" rod.

[Durango_Boy]

Originally Posted by enkeivette

5.7 Rods, $10 for the set!!!
http://cgi.ebay.com/ebaymotors/Set-o...4506.m20.l1116

So what's the reason why those rods...good price by the way...would be better than my 400 rods?

I happen to have a set of forged L82 rods from a 1974 L82 engine...would those be better for my 405?

I'll assume they might not be large journal, but I don't know without measuring.

[enkeivette]

Because I guess apparently the stock 400 rods were only 5.5" rods that short with a 3.75" stroke will side load the pistons too much. You'll have increased wear on the cylinder walls, piston rings, and maybe even poor oil control. Also, a longer rod increases dwell at TDC, increasing high rpm hp.

If those L82 rods measure up, use em.

[big_G]

Don't forget that pistons must match rod length for correct pin placement. 5.5-5.7 and 6.0 inch rods use different pistons. If you already have pistons for the 5.5 rod, they will only work with a 5.5 rod.

[BRUTAL64]

Originally Posted by Durango_Boy

So what's the reason why those rods...good price by the way...would be better than my 400 rods?

I happen to have a set of forged L82 rods from a 1974 L82 engine...would those be better for my 405?

I'll assume they might not be large journal, but I don't know without measuring.

Large journal.
I have a 75 L82 engine on the floor in my shop. It has pink rods. Look at your rods carefully--pink in good.