'302 heads on a 273?

[65Val]

Anyone running the (in)famous '302' heads on a 273? If so, how's it working out for ya? Are they better than the original,say, '67 273 (920's,I think) heads? Is the swap worth it?

Thanks gang!

 

[DusterBoy15]

i cant say but i dont have some for sale

 

[leblanc]

From one coast to the other, too bad I don't know. But had to add my 2 cents

 

[65Val]

i cant say but i dont have some for sale

Oooookay, DusterBoy. Not sure where you're goin' with that, but I already have access to the heads. Just wondering about other peep's 'sperience with'em.

leblanc...and worth every penny too!!...:-D

 

[DusterBoy15]

dam i mean i do have some for sale haha

 

[ValiantMike]

I just installed a pair on my 318, but I havn't fired them up yet. Seems I remember mention of a conflict of hardware on a 273, but to be honest, I'm not absolutely sure. Guess I wasn't much help. Mike

 

[C130 Chief]

Should be a bolt-on if you use a 66-up intake. All OEM iron heads can use the same hardware (non-Magnum). But, the 302 head, while the best of the small port OEM castings, may actually have larger chambers than your 273 heads. As long as you factor that in, they should be a reasonable upgrade on a street 273.

 

[65Val]

Thanks Chief. Yeah, my 273 has a '67 factory 4 barrel intake. I thought I saw a chart somewhere that said that the '920' heads were 65cc chambers and '302's were 63cc's? Am I correct there? Do the '302's use the same cast-in rocker shaft supports as the '920's and at the same height,so I can use my adj.rockers and pushrods?

I'm also thinking this will get me hardened seats (for unlead gas), and the 'swirly' chambers.

Thanks guys. This is great stuff

 

[moper]

I think your 273 heads have a 56cc open chamber... I know the set of '68 318 opens I had were that small. Might want to check into that. The 302s may flow a little better, but it may be a wash as far as chamber size or shape.

 

[daredevil]

check to see that the intake valve clears the cylinder wall is the only thing i can think ofas the chambers may have a larger circumference. may have to notch top of cylnder wall for clearance. looking down bore with heads bolted on will confirm clearance

 

[C130 Chief]

Valve diameters are the same 1.74/1.50 and on the same centers so no bore notch or excessive shrouding issues there. All iron OEM non-magnum heads have cast in place rocker pedestals to include the old W-2 "econo" heads. If you have early high compression pistons, make darn sure there is no dome on them.

 

[65Val]

Valve diameters are the same 1.74/1.50 and on the same centers so no bore notch or excessive shrouding issues there. All iron OEM non-magnum heads have cast in place rocker pedestals to include the old W-2 "econo" heads. If you have early high compression pistons, make darn sure there is no dome on them.

Chief...I'm running the 2-barrel pistons,so, no dome. I stole this chart from another Mopar site. Are these numbers accurate?


Table 1. Chrysler Small Block Cylinder Head Volumes (cc)

Casting Number----Year------Chamber---Exhaust Port---Intake Port
2465315/2658920--1965-1966-----64.5-------60--------127
3418915 ----------1971-1972-----71---------69--------149
4027596-----------1980-1984-----71---------65--------149
4323345-----------1985 -->-------74---------65-------150
4323302-----------1985 -->-------62---------54--------118