318 use 360 heads or 318 heads???

[joey]

i am having some problems....i am building a 318 and it is bored .030 over with a .443 lift 280 duration cam, edelbrock performer and holley 600cfm, i will have block hugger headers as soon as i can find some heads....i need to know if it would be beneficial to use 360 heads milled .030 and 3-angle valve job or 318 heads with 3-angle valve job...i am looking for max hp and low end torque...i am putting this engine in my 88 jeep comanche truck and i was looking for 14s in the quarter...i also need to know what rearend ratio i will need to acheive this...i will me running 2 1/2 inch flowmaster exhaust....well thanks for your help in advance

[360duster]

I would go with a set of 302 castings,they came on mid to late 80`s 318`s in cars & trucks.They are swirl port design & should work well with your combo.With 360 heads you`ll loose some torque over the 318 heads.On the gear ratio,if you plan to drive it much go with a 3.55.If you have overdrive or don`t plan on freeway driving get a 3.91.A 2500-2800 stall convertor would help a bunch too.The 360 heads will give more top end horsepower but all around performance will be better with the #302 heads. KB

[PRO]

joey sounds like a great sleeper!!! the real factor here is what is your comp ratio?to run 14s youll need 9.5:1,as far as heads go all 360 heads(1.88I 1.60E) are open chamber which reduces compresion by .5 or so,early 318 heads(1.78I 1.50E) were closed chamber but small port/valve.So ideally you want the 360 head because of its increased flow as long as it doesnt compromise your compression ratio.The swirl port 318 head of the 80s is a decent choice and can be made to perform like 360 heads,just remember 85-86 trucks used a small port layout that is too be avoided.I'd mill 0.030 if I needed the extra 1/2 pt of compression.As far as max power I dont like the cam you've chosen,is sounds like a general kinetics or sis,in fact I hate it,the MP P4452782(340hp) or P4452761 would be ideal for this app and will out perform your grind(its a chevy grind on a dodge bumpstick..yuk).I dont know what ratios are avail for your rear but I'd shoot for 3.90 or so and run 27" street tires which corrected for tire hiegth gives you 3.60 and 26" slicks for the track which gives you 3.90.Hope this helps ...PRO...ps 315 hp at the crank will net you low 14s at sea level shouldnt be that hard