Building any racecar is expensive...but if you can use parts from various vehicles you can keep the costs down. E.G, Tim's old coupe had Ford struts, because the trick
strut inserts were readily available and bigger discs and calipers bolted on. 10 yrs ago Stanzas and the like were still relatively new. It had a Escort rack fitted because it was lighter than a steering box and drag links etc. The diff was a MK 2 Cortina housing with an Escort LSD because they were far cheaper than Datsun ones and had a good range of ratios. With the wheel bolt pattern matching front and rear it was also far easier to find cheap Ford rims as there were far more of them around...Ford competition parts are still available new from England and they appear expensive but it's all relative , they are new parts not thrashed old bits of #### you see in the Trading Post. Nismo parts are not cheap either...As for what car I'd use for Classic racing well ummm I have a 1200 and my other half has an Escort, both are good cars and there is a wealth of info about on how to make either one a flier. Saw a nice MK 1 Escort a few weeks back nice and low, minilites and standard guards , no flares and it sounded really nice. The interior was really tidy and trad and it ran really hard on the track too. I surprised to talk to it's driver at the end of the day and find it was running a 20 valve Toyota motor with a pair of sidies.!! It would have slipped onto a classic grid easily with no one knowing what was going on. If you go for a Datto look out for a project that is already started as there are plenty still out there..don;t go chopping up original ones as they are becoming rarer by the day!!