1991sleeper

iTrader: (-3)

A customer brought me a 79' K5 blazer with a 400sb in it and originally just wanted a full tune up and oil change.. So I noticed some valve train noise and I told him we needed to adjust the valves ... Then I did the tune up and did a motor flush twice ... Then refilled with good oil and still had valvetrain noise and barely ran better than it did ,but still ran slightly better .. So I popped the passenger side valve cover off and :-o two bent pushrods and both rockers off the valve on #4 ... And it pushed the intake lifter on #4 out the bore so it wiped out the #2 cylinder intake lobe ... ... Keep in mind the vehicle had been setting for 12 years and he drove it here about 15 miles .....

So now he just wants me to rebuild the top end ... Cam, lifters, pushrods, rockers, & timing set , ... It holds a solid 40 psi oil pressure @ idle and 60+ at anything above idle ... U think the bottom end will b OK ? I'm gonna drop the pan and at least flush everything g out as good as possible with kerosene diesel or whatever with engine still in truck ... Is the bottom end gonna last atleast a year or two if I just pit everything back stock and do as I said above ??? Thanks for any help ....

I tried to convince him to just slap a L31 long block in but he said NOOOO I like the 400 lol .... Can u say waranteeee !!! And more power/ fuel economy ... Duh ! Would b a no brainer if this was my vehicle but its not ... He is trying to get this done for 1k$ or less labor and all but we will c ... Cause if I'm building it its getting ATLEAST ROLLER TIP ROCKERS ... No engine should have stamped rockers IMO ...

91' bird 305 TBI T-5, trick flow 175 cc heads, 4.10 gears, lots of suspension upgrades......... 24mpg @ 2300rpm hwy 65mph ........ 8.63@ 85mph 1/8th on street tires... 8.000's soon

ASE doc

I agree that it's a big gamble. But, if the owner is willing to take on the risk that his rebuilt top end will wind up sitting on top of a junk bottom end in a few hundred miles, what can you say? The important thing, from the technician's stand point is clear communication, which you have provided. The gamble is now all his. BTW, I hate cheap owners. I would tell him to take a flying leap on the $1K, give him an estimate and tell him it will take what it takes. But that's your call.

Damon

Whether the bottom end lasts or not isn't your concern. It's a "best effort" repair, no warranty. You're doing what you've been told to do, not what you recommended be done.

Motor oils don't have the Zinc in them they need to work with flat tappet cams any more. Don't go for the megabuck "racing" oils for something like this. Just buy a bottle of Crane Super Break In Concentrate and add it to whatever good quality street oil you would normally use. It's the best of all the break-in additives in my experience. Plenty of zinc, not to high in detergents. Full bottle for break-in of the new cam. Half a bottle in every oil change after that.

1991sleeper

iTrader: (-3)

Yea well I spent 4 hrs researching parts and from what obe gathered minimum 900$ msx around 1500 for top end rebuild n never removing heads

91' bird 305 TBI T-5, trick flow 175 cc heads, 4.10 gears, lots of suspension upgrades......... 24mpg @ 2300rpm hwy 65mph ........ 8.63@ 85mph 1/8th on street tires... 8.000's soon