[Sleeperstang07]

I have a 1968 289 2v that im turning into a 289 4v with a flat tappet hydraulic cam. I purchased a federal mogul engine rebuild kit from summit and I had the engine machined and cleaned up and now im putting it back together with an edelbrock performer dual plane intake manifold and a performer 600 cfm carb. the specs on the new cam are
Lift: intake: 448
exhaust: 472
Duration: Intake: 262
Exhaust: 272

 

[Keving]

What pistons did you get? Flat top pistons will really help you out by adding compression. You are probably adding more than 50 hp if you kept the stock pistons.

 

[Sleeperstang07]

I have flat top pistons by sealed power

 

[Sleeperstang07]

Its also said that the CR is 9.1 with 58cc heads the heads on the 68 are 63cc and the original CR was 8.7

 

[Keving]

I would guess that you are going to be making somewhere in the mid 300s.

 

[Sleeperstang07]

That sounds a bit high. The 289 from 68 put out a very low 195 hp which is very generous (more like 165) so a mild cam and 4bbl carb probably wont make me get up in the 300s.

 

[69moneypit]

I have a 302 with forged, dished pistons with the stock 2bbl heads that have been ported and bigger stainless valves added. They are 58cc heads. My compression is 9.2 to 1. I have a comp cam that has a slightly lumpy idle but dont know the specs. I have the 670 street avenger, edelbrock dual plane performer intake, and clipster shorty headers. C-4 automatic and 3:55 posi rear. Mid 300's ?? I wish. It dyno'ed out at 218 rwhp. Hope that give you an idea of what you can expect.

 

[Sleeperstang07]

haha yeah im expecting something along the lines of 150rwhp tops

 

[v8only]

the 84 mustangs with a similar bottom end and a 4bbl carb setup made around 175 flywheel from the factory through a 2 to 1 to 2 type exhaust

If you put a nice exhaust on it you're looking at 175-200 flywheel hp

 

[Sleeperstang07]

but the 84 was a 5.0 im running a 289

 

[v8only]

a difference of 13 cubic inches...maybe 5 hp.

they're VERY similar....both had nearly the same compression ratio, and both had flat tappet cams...but the 84 comes with better exhaust, a factory aluminum intake and a factory 4 bbl carb...

 

[Sleeperstang07]

good deal so the compression ratio was 8.8:1?