I agree, I have a set of pushrods made by Smith Bros. The one's for my 340 ended up being 7.0", which is quite a bit shorter than the stockers for an adjustable set up.
Get a pushrod length checker to figure out what length you need. Every engine is a bit different, what worked for someone else may not be right for your engine. Remember that deck height (and any square or zero decking) will change the pushrod length, as well as shaving the heads or even running different thickness head gaskets.