do not run rectangle ports on a street mild motor. the port velocity is very slow and have poor low lift flow. the large oval ports are a great head that almost all have 119cc combustion chambers, your 90 heads are 119cc small chamber heads that are great on farm trucks because of the killer torque down low. if you look at flow charts you will notice the low lift flow of small and large oval heads are greater than rectangle heads. smaller ports and more flow means greater velocity. surely you are not going to have a 700 lift cam in this. the low lift flow of .400 and under is the flow numbers you want to see the greatest in street motor with the smallest port possible. 10 to 1 compression is fine on a street big block if the engine is built right. the proper dome with a good cooling system, domes raduised of sharp edges, recommend a hyperutectic piston will give you tighter clearances and a quiter longer lasting engine. keep the spark advance and rpm reasonable. world products,jegs,summit have nice heads for a good price. stock heads cut for larger valves,decked,exhaust pocket ported(manditory on exhaust)bowl hogged,valve job,valves,springs,retainers get almost just as much a new heads for a loss of power.(hint bbc exhaust ports all suck,most gains are there) if you do not do anything with the exhaust ports run a dual pattern camshaft. a performer rpm intake, holley vacuum secondarys or a modified quadrajet(they are up to 850cfm on cads,most smog firebirds with crappy 403s had 800cfm)hooker comp headers, 2200-2500 stall (it will stall higher than rated so don't get a 3500 and think it will be ok. stoc cranks and rods with the best arp bolts and main studs will hold 600 hp easily. 2 bolt blocks are ok, run a windage tray(worth up to 40hp) if you run a flat tappet get the lifters with holes in the bottom and groove the lifter bores, break the engine in with rotella t and run a quality synthetic oil 5w30.


__________________________________________________ _
1985 chevy truck longbed
454 8.11 to1 comp, peanut ports 2.07 1.72 valves under cut slight port job on exhaust only, comp headers(super comps are tight)
stock gasket matched intake(very low corvette)
quadrajet, modified using hp and swap meet books
custom solid cam from crane 116 lobe sep angle, .216int .228exh dur .533 .558 lift had over 18 inches of vac at idle, idles at 750 rpm
good comp pro magnum rockers and pushrods
windage tray and crank scraper and oil pump baffle
1800 stall with 3.08 gears shifting at 4300 rpm ran a 13.52 at 98mph 1.889 60ft with used eagle 33 18.5x15 slicks.(fit under truck with ugly white spoke rims, barely hit third gear
ran quality exhaust with very large diesel mufflers, very,very quiet
4300 lbs plus driver.
ran a rusty toolbox with the battery and nitrous tank inthere,extremely fun with 150 shot of nos
extreme street sleeper than won me a lot of money(poor mustangs and camaros)

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sorry forgot about nos, run the barry grant carb. if it has never been ran and does not seem right i have rebuilt alot of new bgs that have casting problems with flashing and will not run right out of the box. summit does not sell them because of warranty probs of this.(what i was told by my rep) not all had probs. when they run good they are one of the best. i am a bib block freak so if you have any questions just ask.

 

Whats a 772 head?

all I can find on it is that its an open chamber 77-84 454 head...


any good or no?

 

almost all of the large oval bbc heads are decent. i believe the 772 is a large oval truck head with 119cc chambers and 2.06/1.72 valve size. seen cracks by exhaust port/valve area. mostly due to plow and extreme work trucks. most people think its a big block it can handle anything. i will try to find my casting numbers book to be sure

 

#343772.....'68-'86...oval port...Open Chamber...366T, 427T, 454

 

should I pick them up and take them to my machinist?....they look to be in good shape...I didnt see any cracks around the ports or any damage to the valves.

I can get both heads without rocker arms for $50.

Hey MachinistOne... whats the T mean? 366T , 427T

 

t is for truck. get a qoute of larger valves, exhaust porting (bbc exhaust ports are the weak point and really need attention), degrease magniflux, pressure testing, bowl hogging, springs,retainers,new studs because the stock ones are a little short(arps work great) sometimes it is cheaper for new. dart is supposed to have a new aluminum head coming out that flows great and is designed for small ci bbcs and have a (supposedly) low price.

 

I dont really mind spending money at the machine shop,I like to support local businesses..I would rather spend my money there then just have Jegs charge my CC, if the difference is going to be marginal....they are good guys and have always been fair to me...even when I was a teenager

 

Do what Byron said, get them magnafluxed first, you don't need the pressure test, I have not seen BBC heads leak anywhere that did not show up with the mag.

What is your budget?

 

i had one original set of rectangle closed chamber heads that were opened up for more flow on the chambers. they passed a mag and they looked ok but had a small thin spot that leaked when pressure tested. if they are stock pressure testing is overkill.

i am great friends with my machinist and if you ask him i don't have a problem spending money with him, its just that you can spend close to the same amount and not get close to the same performance as a good as cast head. i have seen to many performance shops in our area think they can port and just not quite get it. if the person is not experienced they can screw up a set of heads and lose power but man they looked good. i don't know your machinist but you have to be careful. out of 7 machine shops in our area there is only two that i trust(one does nascar and busch motors, the other used to work for them)

 

yeah...I know what you mean


they guy that has been doing my work builds some good stuff,I have seen some of his stuff do really well in the Silver State open road race and the Big Bend open road race,also some 200mph Texas Mile cars...he stared out doing circle track stuff

 

just compare prices first then decide