help me!!!!

hi all am all new to this forum lark so you will ahve to bear with me lol
I have just inherited a 1988 V8 3.5 V8 Classic with an LPG Conversion off my dad for some fun while he has gone and bought himself a new toy.

The problem i have is that the car is drinking water, have to top up header tank at least once everyday and it is overheating......head gasket i hear you all say....however this has been the problem since it came back from its last MOT and i cant think of what it is.

There are no signs of head gasket failure as it still pulls well isnt burning the water and the oil is fine no salad cream around the filler.

Whilst under throttle the top hose will contract and expand as the throttle is opened and closed......i am no mechanic and i want my baby to work properly!!! i know it needs a new header tank if anyone has a spare LOL as this has been seen to be weeping but i dont know what else to do about the overheating problem....thermostat perhaps???
Please Help i am desperate

sounds conclusively like hgf

i'd say look towards head gasket/liner problem but when you strip it down have a look at the water pump on the way in.

i dont think the hose should pulsate. it prolly would tho if there was a blockage of some kind.

Has it got a servicable expansion cap?

Mines done this although mines is the 3.9 EFI. Expansion cap was not letting the pressure build up due to it being faulty, therefore i lost alot of water and thought it was serious like you.

thanks all for your replies any further help would br gratefully appreciated any other tell tale head gasket failure signs i should look towards?

get the plugs out and see if any are different, keep em in order and describe/post pics of what you find. if one looks steam cleaned then it could be the culprit!