I am building a mild street 455 for my 73 Riv and looking for insight/feedback or any other wisdom before it's all put together. Build will be as follows. Car has stock 2.93 gears with limited slip rear. I am hoping to achieve 450ish HP with this setup. .030 pistons with valve relief 9.7 CR target Iron heads with stage 1 valves and street porting B4b intake Hooker super comp headers Either TA 413 or 298H cam 2800 stall 1111285 distributor Any opinions on this setup? Spoke with TA about this recipe and consensus was it will be a pretty stout setup. Cam recommendations came from them and said TA rollers would help but should be fine with stockers in a street driven car. Let me know what you guys think, thanks in advance!
Check with 71 -73 Riv owners regarding any fit issues with those headers. With that cam you may be close on having enough vacuum to activate your power brakes.
I ran a similar combination for a long time. Although I love TALL gears (I had 2.56), I'm afraid that a 2800 stall converter might slip too much at the lower RPM's you'll have with the 2.93 gears. I would NOT be afraid of a lower-stall converter. (I used a Tri-Shield switch-pitch converter) And if shorty headers are an option for you, they will be easier to fit into the car. I figured that my shorties cost me about 0.1 seconds / 1 MPH in the 1/4 mile over full-length headers - in my own opinion I was happy to give up the 0.1 second in order to have much easier access to everything on the car, easier fitment, etc. -Bob C.
Thanks for your input, the headers I have are hooker 1203, they show Century Regal and Wagons 73-76 for compatibility. TA site shows their super comps fit 68-`77 Special, Skylark, GS, Sportwagon, Regal, Century. `71-`76 LeSabre,Centurion, Electra, Riviera.`78-`88 Regal. I am making somewhat of an assumption they should be close enough in design that the 1203 will fit a Riv like the TA's do. I guess it will be trial and error and modify as necessary to fit them. the 2800 stall is just the one that I happen to have on hand for the TH400, I will look for a source for a lower stall, what would you recommend / 2200-2500?
[QUOTE="j I am making somewhat of an assumption they should be close enough in design that the 1203 will fit a Riv like the TA's do. I guess it will be trial and error and modify as necessary to fit them. [/QUOTE] That assumption is asking for a bad experience. You may even need shorties for your application.
We just put in a set of full-length TA headers on our '73 LeSabre. I am not sure if that's exactly the same as the Riv, but it was tricky to get the reducer to avoid the transmission crossmember. It's in now and it's great, but I kinda wish I'd opted for the shorties, they would have been much easier to install and connect. (I think the old set we took out might have been Hookers, I'm not sure, and the Hookers fit "slightly" better - but we had cut off the collector flange and welded to the rest of the pipes.) Especially where you are calling your engine "mild", I think the Shorties would be better for a bunch of reasons (such as access to the starter motor, etc...) -Bob C.
Thanks Bob, looking at the fitment I was thinking the flanges would need to be cut off and shortened like you mentioned or cut and fab a new hump into the crossmember to make clearance. I knew it would it would take some creativity to make them work but either option isn't a crazy amount of work for me. I scored the complete motor with brand new .030 overbore a TH350, that I'll sell to offset motor build cost, the 2800 stall and the set of headers for $500 so putting in some fab work to make it work in my car is worth it big time for me.
Great - it's all a matter of fabrication skills, and if you can fab a new hump into the crossmember then you're much better than me! And that should make it work great. The only other thing to watch is your transmission temperature, I would go with a substantial transmission cooler. I've seen the transmission temperature gauges but only a few, and I'm not a big fan - but something to consider.
Your stock heads flow just about enough with a Cam change on the Intake side to make that 450 hp and from what I have seen on my flow bench just stepping up to the bigger valve with the right valve job and blending in the air blocking valve guide web will get you enough Intake air for 450 hp, and this will be had with no loss of throttle Response. On the Exh side though I would go with the 1.725" oversized valve but have the heads machined for the less flow restrictive 11/32" stem valves over the bigger 3/8" stockers like you would have with the stage 1 set of valves. This will give you a head start in flow even before the Exh bowl porting work takes place. The 3/8" stem intake valve is not so much a restriction as is that big valve guide support hanging down off the valve bowl roof! Both Intake and Exh valves should get a 29 degree back cut. Make sure the machine shop gives you between a .060" to .070" wide 45 degree seat on the chamber side for the Exh valve. These Heads do not need anything fancy valve job wise with the bigger valve sizes, just a good old 30 top cut, , 45 seat and 60 degree both cut gets it done! Note that the bigger valves will lick up your compression so take that into consideration with the dish you will need in the piston. Be sure to lightly roll over the sharp edge from the head deck into the chamber wherever it sticks out from the head gasket , this way you will have no hot spots at WOT to make for ping and knocking with the iron heads.
