i'm looking to see other peoples opinion on how much horsepower and tourqe i'll be pushing, i'm building a small block 350 4 bolt main motor, the block was bored out .30 to a 355 cu.in., i have .30 over sealed power pistons to drop in, connecting to stock rods and a remanufactured crank, every bearing in the motor is brand new and done professionally, for top end, i'm running an edelbrock performer camshaft and hydraulic lifters with a edelbrock performer intake and a edelbrock performer 650cfm electric choke carb on top, i have power pak heads to put on it that were just rebuilt and a 3 angle valve job was done to them, as well as replacing all the exhaust valves and all the seats and everything, this is going to be the first built motor that i have done myself, its been a tough ride, and i'm sure every one of you guys know that building cars is a money pit and a half, but, just throw your answer in and tell me what you think, i'm looking to back up the motor with either a turbo 350 or a turbo 400 tranny and a posi rear end with 3.73 gears.

 

It sounds good but more info is needed, cam specs, compression, what are the head casting number the power pack heads I remember were 283 heads from the early 60s need valves sizes also.

 

the valve sizes are 1.96 exhaust and 1.60 intake, and they also havetriple springs installed on them,compression is somewhere around 10.0:1, the casting number is 3883520, the stats for the camshaft are as follows:




Duration Advertised
278° Intake/288° Exhaust

Duration @ .050'
204° Intake/214° Exhaust

Lift @ Valve
.420' Intake/.442' Exhaust

Lift @ Cam
.280' Intake/.295' Exhaust

Lobe Separation Angle
112°

Intake Centerline
107°

Intake Timing @ .050"
Open 5° ATDC
Close 29° ABDC

Exhaust Timing @ .050"
Open 44° BBDC
Close 10° BTDC

 

Maybe around 300 hp at the crank with a little more tq. Looks like a nice mild small block, it should have good street manners and even get decent milage.

 

what would you recommend i use for a tranny, i'm planning on bringing it to the track a little bit every here and there but i don't want to be shifting every 2 seconds, so i'm kinda leaning towards an automatic with a shift kit, and what type of a gear ratio should i use inthe rear end, the rear end thats in it right now is just the stock open differential, i was thinking about just keeping that in there till it blows, should i just leave that in there or is the drivetrain to much overkill for it?

 

I think JD is right with the numbers those heads really dont flow all the great relativly speaking not bad for the era though. With those hp numbers a TH350 would work well a Th400 would be overkill and you would lose an extra 10 hp. What year car is it? 3.73s are a good ratio all around if it was dedicated to the strip I would say 4.56 or higher but that is not a good crusing gear. With an open diff 3.73 gears auto 300 hp youshould be into the 9 second range if it was real sticky.

 

its going into an 81 camaro, now, with the stock 10 bolt non-posi rear end that i have onthere right now, would i be able to just swap the ring and pinion and the axles since its already a 10 bolt.

 

I believe you would need a series 3 posi carrier I think the axles are the same if you are going for the gear change dont waste your time put a posi/limited slip in it open diff at higher gear ratios would just burn one tire off. The 10 bolt in the 2nd gens is alot stronger than the earlier 10 bolts and later 10 bolts it would be plenty strong for what you are running. Therereal knowledgable people on this site regarding differentials and hopefully they can give you some advice on what parts to use.