when i first start my car my lifters tick bad and after a few mins it goes away and my oil is full . i think my oil pump is going . if my oil pump is going is that a big job to repair it
It's not a terrible job to change out the pump. First check your oil pressure, if it's below 9lbs at idle, your pump and timing cover is shot. How many miles are on the engine? If it's over 120,000 then the motor is starting to get tired, and the lifters are probably on the way out. Replacing an oil pump may not be the solution if that's the case. To change the pump, remove the 6 or 7 or so many bolts off the bottom cover of the pump, which is holding the oil filter on. The pump drive gears will drop out. If the gears and the cover are seriously scored, remove and replace the timing cover. That's where things start to get get expensive. Timing covers cost a fair bit unless you're able to find a good used one. (Not likely either, it's that engine's weak point) If you don't want to do that, stuff in a high-pressure hi-volume pump kit; it'll buy you a little more time before you have to do some serious surgery on the motor. See the section on 430/455 for tips, tricks and ideas on how to rebuild that motor.
Ticking lifters are caused by them bleeding down. This is caused by wear and tear, not necessarily an oil pump problem. Lifter replacement is an easy job to do, all done from the top. The biggest mistake guys make replacing them is not pumping them up before installing them into the block. If you change lifters follow the directions on pumping hthem up before installing them Pushrod length won't really be a problem, since the lifters operate on hydraulic pressure and compensate for it for the most part.
You're wading into dangerous waters here; - the jury's still not out as to whether pre-priming the lifters is a good idea or not. For nailhead Buicks it's explicitly not recommended to pre-prime or pump up the lifters because the thinking is that the rocker shafts will not be seated and torqued up properly and are subject to premature failure. I'm not sure if the same is true for BBB, but I would think it is. All of the BBBs I've built I've done with the method described below with no problems what so ever. What I've done with all the Buick engines and solid rocker shaft engines I've built over the years is soak the lifters in oil, then lithium grease them into their respective bores, and then soak the whole area down in cam lube. Once the assembly is finished, and prior to the first start, prime the whole oiling system up by placing a priming rod on a drill and priming up the oil pump. This then primes the entire oiling system and pumps the lifters up. Then replace the distributor and run up the engine. When a new set of lifters or cam is installed make sure that your oil has ZDDP in it, otherwise you'll do more damage than starting them dry.
