Years ago I bought an Enya 35 that came with two heads and three venturis. The R/C version of this engine did not come with two heads, did it? There are always a couple of the 5224 R/C engines on Ebay. Which of the heads would the R/C version have come stock with - low or high? I also noticed that the later 35 came with a square venturi. Was this the only change Enya made to the 35? My old Enya 35 took quite a while to break in, and still had great compression years later.