got my 86 LX. Looking for pricing on 351? How much is right for block?

[Lexicon]

I just picked up an 86 LX. I am going to make a straight line car out of this one and was looking at 351 blocks. How much for a 351 block plain. I have found them for a variety of prices, but how much would or should one pay for one that is cleaned and ready to work on? I am wanting to know the highest amount that I should pay for a plain block in Good to great condition. Thank you for the help.

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1994 GT, Performance "Ticket" Red. Stock block with E-303 Cam, 351 "Boss Spec" Heads, Crane 1.7 Rockers, Cobra R Intake, Griffin Aluminum Radiator, BBK 70mm TB, FMS Aluminum Drive Shaft, FMS Clutch "Cobra", BBK Headers, BBK H-pipe, Pro 5.0 Shifter, Zoom Clutch Qradrant. All mating surfaces are port matched and clean, Car is lowered and is factory look. Sound sytem: Sony MD Head Unit, Sony 10-disc with memo Changer, Alpine DSP Equalizer and BBE Center, Image Dynamics Component Drivers (2high