I had the 320temptest with the alpha ss in a donzi minx blue and honey was a great combo

I had a pair of the 350's in an IMP 255 (Magnum splash). X was too high and the thing was a scary, chine dancing, mad boat, but boy was she fun.

basically it was forged crank forged flat top pistons. there are way better cams and heads out there than what was used in the tempest. heck, add another few hp, it'll be a GTO...

Jeff,
Hi there
I know this is old but I would love to get the specs for the Mercury 300 Tempest. Also if you know the GM manifold and carb numbers that would be terrific. Building one up and sure need the info on it.
my email is [email protected]
Thanks
Bill

Hey, I am an auto parts seller. My passion is off shore boat racing. I am looking after old Mercruiser Alpha "SS" Outdrive Lower Unit.

I Think the 300 may be HP, I don't think it is 300 CI, I have never heard of a 300 CI. (But I could be Wrong)
The 300 HP is what it seems to be but wondering what cubic inch motor it was? Now remember it was supposedly in a 1967 boat. What would they have put into a 67 v-drive. I have always heard of the 427 fords with 400 hp but what would be the lesser hp for the v-drive in 1967? It could be that this guy was mistaken and he has a 289 ford block with his v-drive. I do remember seeing a couple from Jacksonville that had a nice white with red stripe v-drive barrel back. I believe it had a 289 in it. Thanks, Tom

Tom, Thanks
Yelp it is a 350ci at 300hp made by Mercury. I scored a manual for it online. I bought one of the 320hp EFI engines with a couple of hours on it but no one knows that EFI system and there are not many parts for it so I am turning it into a 300hp Tempest. They had the same four bolt main bearings, same rotating assemblies with forged crank rods and pistons and a bit of a nice cam. The tempest came with the high rise dual plan manifold but due to height limits I went with a standard GM rodgester manifold and old school Quadrajet carb.
Thanks
Bill

You still got the 320 efi did you end up switching it over to a 300 tempest? Shoot me a call bill 734 752 1271 I would like to buy

Hi there,
Yes i still have the complete system and was thinking about listing it.
Thanks
Bill

Hey Bill you have the whole long block? For the 320efi or the 300 tempest if can give me a call 734 752 1271