Gold Lifetime Member
Join Date: Mar 2006
Location: Wrightsville Beach, NC
Re: engine for 68 project - have a 327 block, looking for advice
Good luck with your project. It's always refreshing to see someone in the hobby brimming with enthusiasm.
All 327's were 2 bolt main, and '68 had all large journal cranks iirc. The small journal were pre-'68.
The engine you have is identical to the ones I use in my '68 Caprice Stock Eliminator drag car. The heads are indeed '290' small block heads, and they are some of the worst castings made by Chevy in the '60s. You will be doing yourself a favor by upgrading to aftermarket offerings or the 'double hump' OE style heads, casting numbers 462, 291, 186, 492, 041, 461, etc.....all are pretty similar. Aftermarket heads will give you better performance over the OE offerings.
Hard to beat a 383, especially in a street car. You can use the block you have, you will have to work with a builder to get a good 'rotating assembly' (aka rotator) which is the crank, rods, pistons.
The block will need to be clearanced for the bigger crank, but this isn't very expensive and almost any reputable shop can do it for 100 bucks or less.
The 383 will naturally make more torque over a 350, 327, and especially a 302. Torque is what you want with a street car more than peak HP.
The 383 will be more expensive to build, easily hit 2K especially if you buy different heads which I would absolutely recommend. The 290 sbc head has small valves (1.72 IV, 1.5 EV) has a large chamber (low compression) and the ports are small and awful overall. I think they are 137 CC intake runners, the OE double humps are 155, and new aftermarket offerings are 180 up to 227 and more.
1968 Camaro NHRA/IHRA SS/C 'Super Stocker' 396/Jerico
1968 Street/Strip Camaro 350 w/PG
1968 Caprice NHRA/IHRA Stock ELiminator O/SA 327-250 HP
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