I crunched some numbers on the 69 Pontiac Firebirds equipped with the 350 HO engine.

Total production Hardtops = 75362
Total production Convertible = 11649
% convertible = 15.5%

Total 350 HO manual WN engines = 2455
Total 350 HO auto XC engines = 2670
% for each is about 3%, so a total production of 6% were 350HO.

Assuming the 350HO was produced in same ratio of 15.5% in the convertibles, that would come out to 686 total 350HO 69 convertibles.

When the ratio of 69 Trans Am's in Hardtop (689) vs. convertible (8) is broken down, only 1.1% were converts.

If the Trans AM 1.1% convertible ratio is used, the total 350HO production would be 59 converts with the 350HO. Assuming this curve wouldn't be linear, it makes the 112 350 HO convertible number believable.

I've seen the 112 total 350 HO convertible number on the web and that is was verified by PHS, but I've not seen this published anywhere. If anyone can verify this I'd appreciate it.

2 cents - Assuming the higher performance engine would reduce the number of convertibles, then the total production for 400 convertible cars would reflect this. Does anyone have the total number of 69 Firebird convertibles produced with either the 400 or 400HO broken down?

I also found the number of Lemans/Tempest 350HO auto XU engines produced was 2800, but I can't verify this, nor do I know how many manual WV engines were produced. If anyone has these numbers I'd appreciate them.