Sounds like a very cool car based on the description particularly its history. Suggest find out what gearbox it's running - if it's a 56a 'box it would be marginal in terms of strength behind that engine especially with the 'no slippage' nature of a twin plate clutch and lock Diff. If it's a 60 or 63 based 'box it will likely be ok - if it's one of these with just standard ratios bear in mind the gear spacing isn't generally ideal for racing but may be ok if it's a good torquey engine.