340 advice

If it was a 'teener or even a 360, I'd go for it- but a 340? Especially if it is a factory 340 car... I don't think I'd chance it. 340s are starting to be worth some coin, and I'd feel better tearing it down and verifying everything. At best, it costs your time and a gasket set. At worst, you saved yourself some serious money and repairs.