the retangular heads arent the best choice for the street on a smaller bigblock.my drag car had a 60 over 454 ,with open chamber oval ports mild port job 2.19 intakes 1.88 exhaust ,12.5 :1 trw pistons with l88 rods and arp bolts.a comp 108 c/l 670 lift offshore marine cam team g intake ,1050 dominator.recurved hei.msd 6al.3:73 gear th350 5500 converter car weighed 3250.10.5 in by 28.5 tire.3"exhaust,1 7/8 hooker headers.all motor went 10.20s-50s.on a 250 plate setup went 9.60s.i drove this to local cruise ins almost every weekend about 15 miles through the city.it was very driveable but the fuel was a killer.race gas only. any way lose the rec heads tighten up the c/l .intakes ok buthere are much better dual planes out there
Make sure those heads will work on a MK IV block I believe there are MK V and if I remeber correctly wont work on your block. Also 396 bores are small and the 2.19 1.88 rectangle port valves are shrouded in a 396.
They are not supposed to work, but they CAN. There is just a little area where the head gasket seals one of the cooling holes at the top of the block just by the thinnest of margins. Mine sealed with a set of Fel Pro gaskets and stayed sealed for as long as I owned the vehicle, At least a couple years, and how much longer IDK.
I think it is going to run great, the duration at .050 is on the edge for a street engine but the 114 lobe separation will help with the idle. I would drop it in as is and run it, should scream to 6500 with no issues and will be a blast to drive. Depending on your first gear ratio of the 4 speed you may need more rear gear, but the torque of the BB helps overcome it.
My dad ran a 65' 325 HP/410 lb.ft 396 in his 68 Camaro for a number of years. 10.5:1 cr, Factory Iron high rise stock iron oval ports with an 1100 CFM Carter spreadbore, Muncie M22 close ratio, 4.11 rear.It DEFINITELY ripped.
One of my favorite BB chevy motors. Had a few of them. Big block power and rev like a small block. I always ran the L88 solid lifter cam. Ran strong and sounded great. Here are the specs on both the early and late L88 cams. Camshaft INT Dur EXH Dur Overlap INT Lift* EXH Lift* PN Early L88 352 364 136 .558” .580” 3879605 Late L88 354 360 133 .560” .584” 3925535 Last one I had was in this Deuce Rdstr. 4 spd with 4.11 gears. It was fast.
Put in and run it, the wide CL will definetely help flatten the torque and make it a bit more docile, a wide ratio trans with a lwoer 1st gr will help launching, once in thepower it wont care about a hair more rpm drop between gears
I spent a lot of time in the late 60's at Englishtown and Island drag strips in NJ.All the run of the mill 325-350 Hp Muscle cars of any brand name ran about the same when stock with the shitty tires. Mid 14's to low 15's. They were all slugs If I remember correctly,the 375 HP 396 was adjusted to 425 hp for stock class.NHRA did that when an engine was underrated by the manufacturer and ran away from the others in the class.Mopar 440 six pack and a few others also had "adjusted" HP ratings. On the streets a well tuned Nova or Camaro with a 375-396 was a bad mother fucker compared to any other Muscle car and could hold it's own against most anything other than all out drag cars.
I think those heads have a non adjustable valvetrain also, so you might want to check and see if it has or can be converted so you do not have to run adjustable pushrods to get the lash right on a solid cam.
The heads are already converted to a adjustable type.Any thoughts on that intake???? Winters #3963569
My opinion is if you like to drive easy and not slip the clutch or have it wind out on the highway, than change the heads and cam or put them in a 454. The real 375hp stick cars ive driven do 3700 4200 rpm at 55 on the highway with 4.11 to 4.56 gears. But on the street they take off nice and easy without chattering the clutch or lugging the engine. Great engine by the way.
My El Camino has the 396-325. Comp 520 lift cam, Eldie RPM with 670 Street Avenger, Hooker headers. Runs really sweet. With overdrive trans it gets 10 mpg on the highway if you drive real careful. Can't afford to drive it much and thats a real shame because its a ball to drive.
Those heads and intake should be fine. The stock compression ratio late 60's - 70 ran from 10.25-1 up to 11.00- 1 depending on the HP. If it is put together correctly and with a good quality carb in the neighborhood of 750 cfm it should be very strong. If its a mechanical cam you will need to make sure it has good strong valve springs and the big rocker studs with new nuts.
I am sure the factory put them into SS Nova's and Chevelles because they were totally lame, had no power, and were slouches compared to all other muscle cars of the era.
375HP,actually the same engine rated at 425HP in a vette was enough for a unibody.L-88 would have twisted the body into a pretzel with out frame connectors.
and they had to have something special for the vette. A guy in town bought a new 396 chevelle in 66, then soon after bought an L88 engine at the dealership, and put it in....ended up with a pretty fast MP car, I think he set a couple records with it, with the tri power
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