87MagnumII

ok i think somebody else has changed this engine before i have. i now question some of rpm issues because this is the casting number on the block, i ran it because i couldnt find a merc serial number tag. the casting number is 3970010. best i can tell it came from a car or truck between 1969 and 1979. hard to tell what kind of cam and other internals got used when somebody decided to put it in the boat. at least with the one im building i know what i have. more pics to come next week when i finish up the new long block and start moving over the exhaust and ignition, water pump, etc etc

87MagnumII

here are a few pics of the timing cover, oil pump and windage tray in place. not getting as much done as I would like too but should have the heads and intake on by friday. forgot to take a pic of the oil pan in place but im sure you can use your imaginations for that

87MagnumII

finally together, just gotta switch the rest over from the old one now

fkboatman

in your post you said it was to be a early 70 s block which is wrong its a late model vortech motor. but looks like very nice.

87MagnumII

the one i took out was a late 70's engine, the vortec i just built is the replacement, you can actually see the old one in the background in a few of the pics. i guess i didnt state that i was building a new engine and not rebuilding the old, sorry about the misunderstanding

fkboatman

you do know the flywheel will not fit new motor, hub on crank is smaller. but you are very smart to run new style vorteck motor.

87MagnumII

I have a brand new fly wheel and coupler

87MagnumII

So today we got around to switching all the accessories from the old motor to the new motor and quickly discovered that the exhaust manifolds would not clear my nice new chevrolet valve covers and I had to put the stock covers back on but other than that all went well and short of running fuel lines and a few odds and ends it should be ready to run in the next few weeks

rbrtbarker3

hey magnum, how big is your concord? i have a 85 mach2 and ran a motor VERY similar to yours. it was a 355 with 9.3-1 comp, sportsman2 heads, cam a step below what you are running, (the ZZ4 cam) rpm intake with a 600cfm holley. i tried a 750 holley, same top end speed but not nearly as responsive as the 600. i would think a 650 would be perfect. i ran stainless marine exhaust with silent choice. took it out, put a set of bearings in it and putting it in my kids 92 S10. And that means i had to go bigger, just put the pistons in it last nite, its a .040 over 400 with flattops and the same sportsman2 heads off the 355. still tryn to decide on a cam. what kind of exhaust do you run? and its nice to see another concord out there!!!

87MagnumII

ok ive been reading some other threads on here and im wondering if this thing is gonna run right with a thunderbolt iv ignition system. any thoughts or comments would be great.

a quick over view of the specs so you dont have to reread the whole thread:
350 sbc with vortec heads, 9.8:1 compression, 650 demon, lt4 hot cam (in218 ex228 lift .525) with 1.6 roller rockers, and a performer rpm manifold