What to do 400 sbc problems

[carssteve36]

Here the problem got a 400 sbc from a guy on this web site ,first the roller lifter breaks in the first 75 miles not his fault I know he does't make the parts that failed.Next 1000miles later white smoke out the tail pipe no big deal pull off the head find 5 head bolt holes heli coiled and block is split .Next pull motor out and take apart and find it is not a 400 but a 377 so know do I keep it a 377 or go to a 406 I have a good 400 block but now I need a crank and pistons to make the 406 witch is what I wanted in the first place .If you think I should post the sellers name I will he doesn't return my emails so I will build it my self this time and I know it's done right. :roll:

[mytmouz]

I have ran both in my avatar truck, both ran nearly identical motor times, the 377 was a tad faster on the bottle. I prefered the 377 simply because I like to twist mine, and the 406 ran out of breath about the time the 377 was just starting to sing. If my 377 stuff was good, and I had another block, I would go back with it, if I had to buy the stuff anyways, I probably would still do the 377, but if you prefer the 406, then it would be the time to do that. All boils down to what you want, and if I was unhappy with the sellers response, I might send them one more message that I was going to throw them under the bus...

[carssteve36]

I have been reading up on the 377 I guess they are a good motor just never had one before the brg spacers took me by surprize is there any problems with them. :?

[mytmouz]

Not to me, but I am a fan of 377's. Never spun a spacer...

[fla1976]

Ran with bearing spacers and never had a problem. I think the 377 is a great engine combo.

[carssteve36]

It did run good and could have got more out of it at the track if I new it was a 377. I was thinking it was a 406 so I tried to tune it has one more gear and a shorter tire should get it done and let it rev . :D

[zipper06]

I always run spacers, plus there's an advantage to running them since the top spacer is grooved, i go 45 degrees and drill a 5/32" hole in the upper main bearing allowing more oil to the mains, i've had 4 or 5 377" motors including the one in my avatar car pictured.

Zip.

[carssteve36]

Iam feeling better now and so is my wallet just the bad work on the block is a joke if the heli coil didn't let go I wouldn't have a clue it was a 377 instead of a 400 but such is life .

[zipper06]

If the original builder would have put plugs in the steam holes and used studs there is a chance that the theads would have never needed hili- coils, i always use plugs in the steam hole and the 3/8" water hole and fill the block to the bottom of the waterpump holes.

Zip.

[carssteve36]

Got the new block friday heads planed put it together my self just got back form the road test 377 makes great power now it's done right . :D

[pistonpopper]

i also run a 377 in my 81 malibu drag car that runs 6.83 (1/8 mi)running the king spacers and never had a problem. i turn it to 7200 , it sure likes to rev. presently running an isky flat tappet. will be upgrading to a comp roller this season and larger carb, to try to hit 6.50 or lower :twisted: