hey bro halfcut basically means getting parts from those kedai potong where certain cars were involve in accidents and no longer roadworthy, therefore they are salvaged for useful parts ie engine...but getting a halfcut requires many considerations especially to people like us who noe very little bout cars....unless u have a reliable mechanic that knows a thing or two and has reliable supplier...otherwise, a few k may be gone buying an engine that has been "trashed" during its prime time...if u understand what i mean.. therefore, if ur iswara engine could still move u around without much difficulties in morning cranking or frequent breakdowns, in my opinion, stick to it

apart from that, ur car shakes upon cruising at 100++ km/p could be caused by many reasons..
first of all, has ur vehicle undergo any wheel balancing or alignment recently? if not, get it done...
2ndly, are ur tires still in good condition? if they are bloated or has uneven surface, chances are, it will shake....if so get it change.....
3rdly, did u have the suspension+absorber checked?..most probably they have worn out after all these years of travelling...changing faulty ones could save u alot in rubber in the future

lastly, if u wan to squeeze more juice out of ur aged engine...you might consider a overhauling of the engine (bear in mind, this is very expensive)..and the result, FC improve and u would get back some uuhhhmmm from it ...additionally, you could change ur exhaust system to a better one?...well this is oso costly....but thats the relationship between power & cost.....more power more costly....

frankly speaking, since u have decided to keep ur trusted pal, and has one house loan on your shoulder....i would recommend u to do what is more important first...ie what is necessary to bring ur car's condition to a safe level...others that doesnt contribute to tat can wait....

cheers

glad to be able to help bro....still learning as well for myself...hope to share my little knowlegde if they are useful

cheers

OOT oso...really ar...thx ar....will chg fast

bro tong1774 : maybe sum tuning will solve that prob of urs bro